Other words in Pakistan's new political lexicon were also inescapable. But the "tsunami" of support Imran Khan predicted would sweep him to power was, on the front page of the Urdu language Nawa-e-Waqt, used to describe Mr Sharif's surge.

Mr Khan undeniably made a difference. It's a remarkable rise from the lone seat his Movement for Justice won in the 2002 poll. And he energised a campaign that inspired new voters, and pushed rivals to re-focus their own pitches to the public.

But all the talk now is of Mr Sharif's comeback, and whether Pakistan itself can move forward after an election which toppled some of the old guard, but gave others another chance.

It was humbling to see old men and women, unable to walk on their own, bent over, and bent on casting a ballot. It was encouraging to see so many young Pakistanis queuing for hours in blazing heat to vote for the first time. It wasn't a perfect election. No-one expected that.

There were Taliban attacks, but more gunfights linked to long-standing political rivalries in volatile cities like Karachi. In all four provinces there were isolated gun battles or bomb blasts.

And, in some places, there were huge irregularities, and heated accusations of rigging.

Many doubted elections would be held at all. Many armed groups wanted to stop them. But the force for change turned out to be greater. Now the results will show what kind of change Pakistan wants..

"We are hoping something new might come, not what was repeated for 66 years," comments 24-year-old Qadeer Zarkoon, as he and a group of students settle in for another an evening of lively discussion at Cafe Bol.

This informal gathering space, like most of Pakistan, is torn - between savouring a new sense of change, and still fearing the future.

"It's the first time ever in our history an elected democratic government completed its tenure," Qadeer points out. "At least it paves the way in the direction of democracy."

Pakistan entered this election encouraged by a rare achievement in a country ruled by the military for about half of its history. The last elected government managed to rule for five years without being thrown out by political machinations or a coup.

But that accomplishment was then followed by a campaign marred by unprecedented violence.

"How can we make a difference when constituencies are targeted on a daily basis by bomb attacks?" mourned 21-year-old political science student Zeeshan Yousef.

"How can we even be sure who we are going to vote for if the parties are not allowed to present their manifestos?"

Across large parts of Pakistan, attacks by Taliban and other militant groups mainly against more liberal political forces, meant some parties were hardly on the hustings.

As the discussion continues at Cafe Bol, you can feel the political heat rising in a cosy room, only about 6m by 3m (20ft by 10ft), tucked away in a vast warren of shops. Lit by candles, and cooled by paper fans on another night of power cuts, the atmosphere is deliberately rough and ready for a raw debate on the issues.

Bol means "speak" in Urdu. It was a rallying cry during the 2007 Lawyers Movement, a groundswell of protest against the sacking of the chief justice by the then-leader General Pervez Musharraf.

Many in Pakistan see intense engagement by civil society as a spark that still fuels some of the great enthusiasm in these polls - in spite of the violence.

"Resistance in Pakistan is something every generation has experienced and been part of," reflects lecturer and Cafe Bol co-founder Qalandar Bux Memon.

And for at least some in this generation, the elections are a political coming of age.

Forty million young Pakistanis are eligible to vote for the first time. The charismatic cricketer-turned-politician, Imran Khan, has been able to tap in to that yearning for change. Other parties have latched on to the same mantra of "Naya (New) Pakistan."

I've received messages on social media from young people living in volatile cities like Karachi and Peshawar that they are determined to cast their ballot, no matter what.

Others are understandably cautious.

"People are very scared," commented 22-year-old Amin Ullah, who is from the sensitive province of Balochistan, under army rule after a wave of sectarian violence. "I think only 20% will vote there."

It would be wrong to see a youth wave as a monolithic force for change.

A recent British Council survey of young Pakistanis between the ages of 18 to 29 found only 29% believed democracy was the best political system for the country. Military rule scored higher.

"In urban areas, there is real engagement," comments 23-year-old Ali Moeen Nawazish, who was recently appointed as a "Youth Ambassador" by Pakistan's popular GEO News TV.

"In more rural areas, it's not as evident," he said when we met in the capital Islamabad. "The 'breaking free' has yet to happen."

At Cafe Bol, college students think the answer to Pakistan's woes lies in political change.

"There are many problems", regrets Qadeer, "but the solution is more democracy."

"We feel the power," declared 22-year-old Moussa Ghaznavi, the son of a rickshaw driver now studying media science.

"But we fear corruption, fear flawed elections, fear that if this happens, the dream won't be there anymore. "

But as we step out of his four-wheel drive vehicle, the veteran campaigner is showered with crimson petals by an enthusiastic crowd.

A crescendo of "Wazir-e-Azam! (Prime Minister) Sharif" rises from excited loyal supporters. A few even push forward to slip fragrant garlands around his neck.

Old habits die hard in Pakistani politics. But this time, politicians are being forced to change. Taliban attacks have made the rousing road shows and rambunctious rallies of old simply too dangerous.

But two-time Prime Minister Nawaz Sharif and rising star Imran Khan weren't on a Taliban hit list during what's being mourned as the bloodiest ever election.

The two men have been campaigning hard. And I joined them both on the trail in the past week.

Travelling with them, you're thrown into the chaotic carnival atmosphere of elections past.

But at most public gatherings, rowdy crowds are kept back at safer distance. Speeches are shorter.

Advisers place bullet-proof glass shields on podiums but both men make a point of removing them. They resist wearing protective armoured vests.

Family members say Imran Khan finally succumbed to their pleas, and will always be grateful he did. A vest cushioned his fall from a forklift at an election rally on Tuesday and, it's said, probably saved him from serious spinal injury.

Private jet

As a closely fought campaign goes down to the wire in Pakistan's most unpredictable poll, Imran Khan is sending his last appeals from his hospital bed and Nawaz Sharif is sharpening his slogans.

Imran Khan's slogan of "Naya (New) Pakistan" has clearly excited large numbers of young voters and lured apathetic middle classes from their drawing rooms.

But Mr Sharif bristles at suggestions his rival has the monopoly on the magical mantra of "Change".

"Our slogan in the 1990s was a slogan of change," he tells me as we take off in a private jet that allows the wealthy industrialist to travel in style, speed, and safety. He cites how his Pakistan Muslim League had opened up the economy, and maintains he would have accomplished much more had both his terms not been cut short by coups and conspiracies.

"We have people, we have done it before," he emphasises. With a swipe at his rival, he adds: "We don't need immature people."

On the plane, his aides hand him the latest press clippings which predict he'll be the next prime minister. With a broad smile, he shows me a text he's received on his mobile phone - stock prices have risen to record highs on that expectation.

'Revolution'

If one of Nawaz Sharif's selling points is that he's "good for business", Imran Khan is roaring to new political heights with a vow to end "business as usual".

He's already changed the usual ping-pong in Pakistan politics between Mr Sharif's Pakistan Muslim League and the Pakistan People's Party which once defined itself by "people power".

"This is the beginning of a revolution in Pakistan," Imran Khan exclaims above the screech of helicopter blades whirling for lift-off.

"This is an uprising from the grassroots. We've completely bypassed the traditional politicians."

On a whirlwind tour of the north-western province of Khyber Pakhtunkhwa, which has seen the worst of Taliban attacks, I point out that he can hold these public gatherings because he hasn't condemned the violence.

"I am not pro-Taliban," he retorts as he prepares to address another rally. "I am anti-war. All the parties now recognise there is no military solution."

Then he takes to the podium to denounce what the Americans used to call a "war on terror". He vows to shoot down any US drones operating in tribal areas along the Afghan border.

The former cricket captain, known in the west as a charismatic playboy, also pledges to establish a model Islamic welfare state.

That message resonates in one of the most conservative parts of Pakistan.

Free laptops

The stage behind him is heaving with local politicians, hangers-on, and Pakistanis who have flown in, everywhere from Luxembourg to Australia, to be part of this moment.

Three young Pakistanis, just out of medical school, wait at the edge of the platform to get their pictures taken with their new hero. "We're voting for the first time," they tell me excitedly.

I point out they had been old enough to vote in the last elections in 2008.

"We weren't motivated then," explained 26-year-old Hammad Khan. "Even my grandmother is voting for the first time because of Imran Khan."

A decade ago, when Khan struggled to win any seats he was mocked: "Your supporters are all kids." He shot back then, "They'll be voting in 10-12 years." And so they are.

Nawaz Sharif insists he's also attracting some of that precious vote bank. Forty million young Pakistanis are now old enough to vote for the first time. His election rallies in Urdu are peppered with the English words "laptop" and "motorway". Building roads and distributing free laptops are his signature programmes.

But his favourite punch-line of all is: "I played cricket too, but it's not the only thing I've done."

At a packed gathering of shopkeepers in an Islamabad hotel, he adds, to rousing cheers: "I also made the atom bomb."

That goes down well in a country that hailed Pakistan's entry into the nuclear club when Nawaz Sharif was in power.

Now the nuclear state does battle with constant power-cuts crippling the economy, violence tearing the nation apart, and corruption eating into all parts of life.

Whoever wins this election also wins the hardest of jobs.

Imran Khan, a rising political star, took a fall.

Images of the country's former cricket captain tumbling from a wooden lift next to a stage played over and over again on Pakistan's many 24-hour channels.

And, with his fall, the political high ground rose. His chief challenger, Nawaz Sharif, declared at his rally he was cancelling his campaigning the next day in sympathy and solidarity.

Political leaders across the spectrum sent wishes and offered prayers.

President Asif Ali Zardari sent flowers to the Lahore hospital where Mr Khan was under observation after suffering a head injury that needed several stitches.

Suddenly, there seemed to be a rare moment of fair play on the political playing fields.

After weeks of denouncing and demeaning each other, bitter rivals ended the invective.

Across social media, where this election has a life of its own, comments poured in to commend Mr Sharif, the two-time prime minister now facing the fight of his political life against Mr Khan.

"Fantastic maturity"; "brotherly spirit"; "classy" were just some of the adjectives spilling across a Pakistani Twitter timeline.

But in a country where political debate is a popular sport, others landed a harder punch.

"All busy scoring points," wrote one tweep.

Pakistani writer Abbas Nasir, commenting on Mr Sharif's move, tweeted: "Shrewd political manoeuvre rather than a gracious act/gesture. Should be seen as such. Probably work too. "

British Pakistani writer Kamila Shamsie tweeted me to say: "That is fair play but then we have to ask: Why have there been no suspended rallies when candidates are killed?"

Her message came from the southern city of Karachi, where candidates and party offices are attacked almost daily by the Pakistani Taliban, who've declared this election unIslamic.

Three major parties are on their hit-list, but not Mr Khan's Movement for Justice or Mr Sharif's Pakistan Muslim League.

On the same day as Mr Khan's accident, a bomb targeted the brother of a candidate for the Pakistan People's Party in north-west Pakistan. Zahir Khan was killed along with five others.

Neither Nawaz Sharif nor Imran Khan has come out strongly in this campaign to condemn the violence against their rivals as a brutal assault on democracy.

"Three provinces are facing dire violence but unfortunately the political parties have not got together on a common platform to unite against the Taliban," said Pakistani writer and journalist Ahmed Rashid.

Both Mr Sharif and Mr Khan offered defensive replies when I asked them about their ability to campaign in relative safely, while others were under major threat.

Mr Khan insisted he wasn't pro-Taliban. He described himself as anti-war and emphasised it was time to talk to the Taliban.

Mr Sharif protested that he had expressed sympathy with victims and their families, and that his party had been targeted too.

The debate is certain to go on until election day and beyond over whether sympathy votes will now go to Mr Khan as he emerges, bandaged, from hospital to continue the fight.

And whether Mr Sharif's response was shrewd or sympathetic, will the man who's been regarded as the front runner escape any political injury?

As the day began, the popular Dawn newspaper cartoonist Zahoor had depicted Imran Khan painting a portrait of a smug Nawaz Sharif falling from a cliff.

When the day drew to a close, it was all about Mr Khan falling from a stage.

And from his hospital bed, the wounded politician spoke: "On May 11th, consider this your battle, it's not just my battle, it's a battle for this country."

A televised moment of high drama sent spin doctors, on all sides, into a tail-spin.

No-one can say with certainty here what the next day, next rally, and this next election, will bring.

There's another message on the back of black T-shirted elite anti-terrorism police - NO FEAR, in bold white capital letters.

And it's not just well-trained muscled gunmen at campaign rallies who want to say they're not afraid.

Leaders of three political parties, publicly threatened by Pakistani Taliban, or TTP, stood shoulder-to-shoulder and announced this week they would not be cowed by their threats of violence.

Not a day goes by without election attacks and deaths on the front pages of Pakistani newspapers.

Despite that, opinion polls are indicating there could be a record turnout, higher than the 44% in the last elections in 2008.

That's partly because of a surge in young voters. An estimated 31% of the electorate is between the ages of 18 and 29.

"You could say these are the first youth elections," writer and former Pakistani Ambassador Maleeha Lohdi told the BBC. "There's also a new enthusiasm among all voters which is good news for Pakistan."

'Eye-to-eye contact'

As we start our Pakistan election coverage, we've attended election meetings and rallies in the capital Islamabad and in the most populous and relatively peaceful Punjab province.

Party leaders like Nawaz Sharif and Imran Khan make a point of removing bullet-proof glass shields from their speaker podiums to address large crowds now being held back at a safer distance.

"It's better to have eye-to-eye contact," PML-N leader Nawaz Sharif told me before one rally this week in Sarghoda in Punjab.

"We're still going door to door, shop to shop, where we can," said Shafqat Mahmood, a candidate for Imran Khan's PTI party in the city of Lahore.

Campaign organisers admit they've had to cancel rallies planned for volatile cities like Karachi in the south, or in the northwest close to the tribal areas, for security reasons.

Some parties, including the Pakistan People's Party (PPP), are being accused of using the threat of violence as an excuse for lacklustre campaigns and what's expected to be their dismal performance in some areas on polling day - the more usual danger in democracy.

But the danger of violence is all too real. In sensitive areas like Balochistan province, there are reports some election workers don't want to man polling stations because they fear for their lives.

The Pakistan army has announced 70,000 troops will be deployed in four provinces on election day, along with thousands of police and other security forces.

The 11 May election will be not just one of Pakistan's most important elections. It will also mark another decisive showdown between forces determined to shape this country through violence, and those who still believe the ballot box matters in trying to resolve Pakistan's growing crises.

Lyse Doucet's reports from Pakistan will feature on BBC World News and Newsnight next week.

I've covered almost every one of them since 1988 when martial law abruptly ended and a people who fought for democracy directed their energies and enthusiasm towards the battle for ballots.

What boisterous campaigns there've been - massive rallies that packed stadiums and fields, convoys of vehicles snaking, horns blaring, through villages and down highways - a chaotic carnival in every constituency.

But elections in Pakistan can't be like that anymore. It's simply too dangerous. Not a day goes by without a report of an attack by one of many armed groups on a politician, or a public space, or the police.

I'm back in Pakistan to find out what it's like to campaign in "Elections 2013", and what it takes to win.

The crush of massive crowds has mostly been replaced by "corner rallies". Politicians travel across the land in helicopters on carefully guarded schedules, rather than spontaneously weighing into the fray.

Something has been lost. But something else has been gained. A different kind of explosion has transformed the political landscape here.

There's a dizzying array of television channels in all the languages spoken here. And social media provides the safest of places to argue and analyse, and of course to jockey for influence and joke. It wouldn't be Pakistan if they didn't.

Another chance

Many worry about "saving Pakistan" - from the blight of official corruption, growing violence and extremism, deepening divisions. That's on top of the age-old problems of poverty and illiteracy.

Everyone talks of "change". Everyone has waited a long time for it to happen. Will it come, this time, from within the parties which traditionally dominated politics or will it usher in the rise of new political dynamic?

Yet again, this is an election where people warn that Pakistan "at a crossroads", is facing a "last chance".

Despite all the threats and disappointments, every person I have spoken to - so far - told me: "Yes of course I am voting!"

Pakistan always seems to get another chance. And yet again, you sense that at least the people want to seize it.

Once more, I'm following another Pakistani election, and this time will be posting updates on this page.

Now alleged war crimes are being pushed onto the agenda of the Commonwealth.

"Bad things happen in war, but there has to be a full accountability by both the government and the opposition for war crimes," Canada's Foreign Minister, John Baird, told me on a visit to London for the Commonwealth Ministerial Action Group (CMAG).

Canada is now leading the charge to deny Sri Lanka the privilege of hosting this year's Commonwealth Heads of Government Summit in November unless it makes progress on a list of human rights concerns, including "meaningful reconciliation" with its Tamil community.

The UN says at least 40,000 civilians, mainly Tamils, died in the last months of the protracted war between government forces and Tamil Tiger rebels. Other sources say the real figure is much higher.

"We find it absolutely appalling that Sri Lanka would be taking on a leadership role in the Commonwealth," emphasised Mr Baird after a meeting of the CMAG, which describes itself as "the custodian of Commonwealth values and principles".

Sri Lanka is hitting back in equal measure.

In a telephone interview from the capital, Colombo, cabinet spokesman Keheliya Rambukwella accused Canada of being "very biased, very unfair".

Asked about calls from Canada and leading human rights groups for an independent, international probe into accusations of war crimes, Mr Rambukwella repeated his government's rejection of outside involvement, saying it had its own commission and reconciliation process.

The cabinet spokesman accused Ottawa of playing to the large Tamil diaspora in Canada.

Despite Sri Lankan government efforts to rebuild areas ravaged by years of war, Tamil communities outside and inside the country remain critical of Colombo's efforts to reintegrate a population still deeply traumatised by a devastating war.

Mr Rambukwella insisted: "The Tamil people are much happier today."

With only months to go until November's summit, it is not clear what impact Canada's very public intervention will have.

Bangladesh's Foreign Minister, Dr Dipu Moni, told the BBC World Service's Newshour programme that her country would attend a summit in Colombo, but said: "We are urging our close neighbour and friend to take all necessary steps to fulfil accountability."

Commonwealth Secretary General Kamalesh Sharma said on Friday that he saw no reason to deny Sri Lanka the honour of staging the next summit.

He told a news conference in London that Sri Lanka was "engaged and willing" to improve the situation.

However, Mr Baird said he had seen nothing to cause him to advise Canada's Prime Minister, Stephen Harper, to change his position on Colombo's human rights record.

Yet again, this 54-member organisation - mainly former British colonies - is confronting divisions in its ranks on human rights.

In recent years, heated arguments over everything from gay and lesbian rights to military coups have made their way onto their agenda.

Mr Baird pointed out that the Commonwealth recently "raised the bar" by drawing up a charter that details "shared values" of democratic development and human rights. It was signed by Queen Elizabeth, who heads the Commonwealth, last month.

"I think this is a real test," Mr Baird emphasised.

A "right to defend itself, by itself" is invoked a lot by Israel these days.

Asked whether President Obama had given Israel what is often referred to as a "green light" to act militarily on Iran, Mr Netanyahu quipped: "Israel's right to defend its existence is not subject to a traffic light."

A number of people close to the prime minister have emphasised, in conversations over the past year, how Mr Netanyahu sees stopping an Iranian atomic bomb as his "mission".

"It's in the prime minister's DNA," said one senior Israeli official.

Last year he had railed against the United States for allegedly stopping Israel from taking military action, if necessary, to stop Iran's nuclear programme. Iran continues to insist its programme is entirely peaceful.

Israeli officials underline how it rankles Israel not to be able make its own decisions when it comes to its own security.

But Mr Netanyahu's confidence has been bolstered by what he and President Obama now refer to as "unprecedented" military and intelligence cooperation on this issue.

"He seems more relaxed now," reflected the BBC's Iran analyst Kasra Naji.

Last September the Israeli leader grabbed world headlines at the United Nations when he drew a crude cartoon bomb slashed by a red line, which he warned Iran would not be allowed to cross.

Then, he predicted they would be at that point by this spring.

But when I met Mr Netanyahu in London this week, he told me Iran had not surpassed the threshold of enriching enough uranium to move quickly towards a bomb. "They've sort of crept up but not crossed it," he said.

I pressed him on how much time was left on the clock. There's "less time", was all he would tell me.

Western diplomats say Iran is now being "very careful".

In recent weeks, both Mr Netanyahu and his Army Chief of Staff Benny Gantz have made it clear that not only is Israel ready to strike militarily, if necessary; they say Israel also now has the military means to do so.

"Israel has a military option on Iran," said one senior Israeli official who would not go into further details.

But Mr Netanyahu said he didn't want to "get into the discussion" about the significant opposition he faces at home from a nervous Israeli public and security establishment which worries a controversial military strike on Iran's heavily guarded nuclear installations could spark a regional war.

But Israel has a more immediate concern right now - a deteriorating situation next door, in Syria. On this front, Israel has taken action, and Mr Netanyahu made clear, would do so again.

What he told me hinted at a more interventionist approach.

But he refused to go into details on what he called "Israel's constant plan to defend itself".

The prime minister wouldn't confirm what Israeli officials have told the BBC privately - that Israel warplanes targeted a Syrian government weapons convoy in January reportedly en route to Hezbollah fighters in neighbouring Lebanon.

But he stressed, "I'm sure the leaders of Syria, whatever is left of Syria, understand that Israel will always take action against those who attack it." Then he added, "The question is: do the terrorists who operate in Syria understand that?"

He underlined Israel's growing concern over the rising strength of Islamist groups operating in Syria and the risk that "very, very dangerous weapons" such as anti-aircraft and chemical weapons could fall into their hands.

It's understood Mr Netanyahu discussed the arming of Syria's rebels during his talks with Britain's Prime Minister David Cameron.

Britain, as well as France, is calling for an EU arms embargo, which runs out next month, not to be extended, so that arms can be provided to rebel groups.

"I have one question," he said "which rebels and which weapons?"

He clearly recognises there are no good options on Syria right now. In his words, "It's the bad fighting the bad."

The entire neighbourhood is worrying Israel.

"This is a Middle East that is imploding and instead of having the Arab Spring produce the hopeful revolution of the Google kids taking over, what we're seeing in many lands is the opposite."

Israel is accused of isolating itself by not moving more decisively and convincingly on peace-making with the Palestinians.

Mr Netanyahu reiterated his support for "a two-state solution", including a Palestinian state.

But many doubt his true commitment given that his new coalition government is dominated by settler leaders.

And just this week, his housing minister Uri Ariel of the Jewish Home party said it was Israel's "right and obligation" to build new homes in the sensitive area known as E1, near Jerusalem in the occupied West Bank.

The EU has warned that such a move would represent the biggest threat to the two-state solution.

US Secretary of State John Kerry, who's just finished another trip to the region, cautioned that only two years remained before the window of opportunity closed on a Palestinian state.

Mr Netanyahu made it clear in our interview he will act on Israeli fears, to defend his country. The question many ask is whether he will also act on the hopes of those who still believe a two-state solution is the best way to help strengthen the security of Israel.

And now support has come from an unexpected group - Israeli ex-spy chiefs.

"All of the living heads of Shin Bet felt it was about time that people in Israel and the rest of the world heard their voice," explained Israeli filmmaker Dror Moreh.

He has pulled off a journalistic coup in persuading six men, who headed Israel's internal security agency from 1980-2011, to be part of his remarkable Academy Award-nominated documentary, The Gatekeepers, now showing in the UK.

"All of them are for a two-state solution," he told me on BBC World TV's Impact programme.

The film centres around six very personal outspoken accounts from men who oversaw Israeli operations, from targeted assassinations of Palestinian leaders, to surveillance and torture.

Their emotions range from professional pride to expressions of unease over the exercise of their formidable power.

"These men had to make highly difficult security decisions, on the spot, leaving politics aside," commented Paul Charney, chairman of the Zionist Federation of the UK, who joined our discussion.

"Now they can discuss, for the first time, their own moral fibre, their own politics, for the rest of the world."

"What comes through powerfully in the film is their sense that the best they can do is create some political space for others, the political elite, to step in to do what must be done," remarked Daniel Levy of the European Council of Foreign Policy, who's had extensive experience in Israeli-Palestinian peace-making.

That means "talk to the Palestinians, end the occupation."

Some have described The Gatekeepers as a challenge to Israeli Prime Minister Benjamin Netanyahu, who now heads a coalition government which includes key members publicly and passionately opposed to a two-state solution.

"At the end of the day, the Prime Minister of Israel said exactly four years ago to the day that he is for a two-state solution," emphasised Dror Moreh.

"But what we have seen on the ground has gone completely the opposite way with settlement building that is larger and deeper."

"I think this is why they all came to this film," he reflected. "It's really the last opportunity to reach a two-state solution."

But can it be soon enough to ease growing anxiety over Iran's nuclear programme and stave off more crippling sanctions?

"Another failed diplomatic foray is likely to prolong the standoff and increase the price each side has to pay for a compromise," commented Ali Vaez, senior Iran analyst at the International Crisis Group (ICG), who was in Almaty.

The only common ground between Iran and six world powers seemed to be recognition of how far they still have to go to negotiate a way out of this crisis.

Time is not on their side. US Secretary of State John Kerry, now visiting the region, warned talks cannot last forever.

"There are four lanes, each with a different clock," commented another long-time observer of these tortuous talks.

He pointed to the speed of Iran's nuclear work, Israeli military threats, and deepening sanctions, alongside the negotiations.

On the negotiating track, the lane is still open.

"We're hopeful that P5+1 and Iran will meet again to resume our dialogue," said a senior US official in Almaty, referring to the five permanent members of the Security Council, plus Germany, tasked with the nuclear file.

The official didn't rule out another round before Iran's presidential election in June.

And it's also clear that, in this latest round, there was more talking in the talks than ever before.

"My colleagues, some of whom have been doing this for a decade, had never seen anything quite like it," remarked a senior American official. "Rather than stilted and overly formal exchanges we had an intensive dialogue on key issues."

But what world powers didn't get was what they say they need to make any progress: a concrete, comprehensive Iranian response to their "fair and balanced" package first put on the table in Almaty in February.

It puts the onus on Iran to take the first confidence-building step. That's reported to include a six month suspension of the 20% uranium enrichment programme regarded as dangerous. Incentives include modest relief from sanctions.

But Iran's chief negotiator, Saeed Jalili, insisted: "Confidence building is a two-way street."

Sources say Iran is ready to stop 20% enrichment but only in return for a full lifting of sanctions. That's a step the international community won't take.

Conversations with Iranian officials also underscore their demand for a clearer sense of the "end game".

What will be the final shape of Iran's nuclear programme and the scale of sanctions if it halts some of its most sensitive nuclear work?

Essential for Iran is recognition of what it regards as its "inalienable right" to enrich uranium, enshrined under the Nuclear Non Proliferation (NPT) treaty.

Western diplomats disagree with Iran's interpretation. They also point out that the International Atomic Energy Agency (IAEA) would have to certify that Iran's nuclear programme is entirely peaceful, which it has so far been unable to do.

On both sides, there is still too little trust and too much inflexibility.

"The structure of the P5+1 deal makes a deal almost impossible," commented one informed observer in Almaty who said Iran could not work with the proposed sequence of steps.

One Western diplomat admitted as much to me.

"Iran's delegation can't go home and say it is a good offer," said the diplomat.

"Dr Jalili may want a deal but it's Iran's spiritual leader Ayatollah Ali Khamenei who calls the shots," he remarked with frustration, describing negotiations as "political theatre".

In this play, both sides read from a different script.

Playing to a domestic audience, Dr Jalili said the P5+1 had to return to their respective capitals to evaluate "Iran's proposed plan", implying the ball was now in the other court.

A senior US official said "All of us need to evaluate what the next steps should be in this process and think through how we can move more effectively to get there."

Some observers hold out hope that Iran may come forward with new ideas after its critical elections are over.

But no matter how diligent diplomats are, the clocks are also ticking on the other lanes.

"The time has come," said a statement from Israel's Minister of Strategic Affairs, Yuval Steinitz, "for the world to take a more assertive stand and make it unequivocally clear to the Iranians that the negotiations games have run their course."

Both Western and Israeli sources say Israel is holding fire, at the moment, aside from its verbal barrage.

And one Western official said Tehran was, for now, being "very careful" in its nuclear programme. It recently confirmed it had resumed the conversion of medium enriched uranium into oxide fuel to slow down growth of its stockpile.

On the sanctions front, more penalties are pending.

"The US president can't push back sanctions when diplomacy is going nowhere," emphasised Ali Vaez of the ICG.

But world powers, bitterly opposed on key crises like Syria, are still finding enough common ground when it comes to Iran.

Russia's chief negotiator, Sergei Ryabkov, spoke of being "still on the threshold" in remarks to the Interfax news agency.

"There may not have been a breakthrough but there was also no breakdown," was how a senior US official summed it up.

But without a break in the stubborn deadlock, pressure will mount, surely and steadily, on all fronts.

"Some good negotiations," were the words used by Iran's Chief Negotiator Saeed Jalili.

By all accounts, there was more talking in the talks than in the past decade of tortuous negotiations over Iran's nuclear programme.

But it's underlined how wide the gaps are, how deep the mistrust is, how far they still have to go to achieve a negotiated solution.

And time is not on anyone's side. Both sides are under pressure to prove talks are not failing. But there was no agreement, not even on a date to meet again, although consultations and telephone calls are in the diaries.

Both sides believe the other is still asking for too much, for too little in return. Both believe the ball is in the other's court. But the onus still lies on Iran to prove its nuclear programme is entirely peaceful, lest calls for military action grow ever louder.

Masterful words of an American president, delivered with empathy and eloquence, carried force to charm a sceptical Israeli public.

But do they have enough power to push Israelis back to the negotiating table with the Palestinians?

"We need to take a very long breath now," sighed 27-year-old Avinoam Rozenbaum the day after he sat with some 600 other Israeli students to listen to Barack Obama's main speech during his three-day visit to Israel and the Palestinian territories.

"I'm still digesting it," he told me when he came in to our studio in Jerusalem, still visibly affected by the privilege of sitting in a front row of history.

President Obama's carefully crafted "story of Israel" wove an arresting narrative of freedom - from the sacred Jewish holiday of Passover, through the establishment of a Jewish state, to the right of Palestinians to also be "a free people in their own land."

Avinoam heard first-hand the president's call to "the young people of Israel… to write the next chapter in the story of this great nation".

Our conversation brought in a 21-year-old Palestinian student, Karma Abu Ayyash, who watched the speech on television in the West Bank city of Ramallah.

"It gave us hope," she said, speaking from our BBC studio there.

President Obama's message to both sides was that only direct talks would achieve what must be the main goal - "two states for two peoples."

I asked Avinoam and Karma what they would say if they sat across from each other at that negotiating table.

"You must try to see what life is like for us living under occupation," emphasised Karma, echoing the president's call to Israelis to "put yourself in their shoes."

"We need to focus on the future," Avinoam replied just as firmly. "There is no guilty or innocent side."

He took issue with the American president's description of peace as "just".

A young Palestinian studying business and an Israeli doing a Master's degree in diplomacy voiced some of the same sentiments of an older generation who've lived through the decades of tortuous talks marked by violence and venom.

The woman who will sit at the table if talks re-start also spoke of new hope.

"He put peace-making back on the agenda," remarked Israel's new Chief Negotiator Tzipi Livni, who praised a speech she described as "brilliant."

The former foreign minister, one of the few Israelis to highlight deadlocked peace talks in recent elections, has just accepted the job of justice Minister in her rival Benjamin Netanyahu's coalition government.

She dismissed suggestions she was the "fig leaf" in a new team dominated by settler leaders and right-wing opponents of peace.

"I wouldn't have joined this government unless I thought Bibi [Netanyahu] understood he has to move forward."

But when I asked her if she agreed with President Obama's view that Israeli settlements were "counterproductive to the cause of peace", she spoke only of the need for Israel's new team to discuss their negotiating strategy.

Israeli settler leader, Danny Dayan, who was also invited to join the audience for the president's main speech, was more emphatic."

"We need more Tony Blair and less John Kerry," he explained when he sat in our office.

As he sees it, it's an approach that emphasises economic cooperation and Palestinian institution building rather than what he dismissed as the new US secretary of state's ambition to "solve it all".

But words like settlements are the ones that matter to Palestinian politicians. And President Obama's remarks on that issue deeply disappointed them.

"It's either settlements or negotiations," insisted Palestinian MP and activist Mustafa Barghouti. "Continued settlement building on occupied land will mean the death of a two state solution."

For Palestinians who hailed President Obama's call in 2009 for a settlement freeze, his less forceful language this week was a step backwards.

During this first visit to the Palestinian territories as president, Mr Obama called for negotiations which "get out of some of the formulas and habits that have blocked progress for so long."

These stubborn gaps will now be addressed in painstaking detail by John Kerry when he stays in the region after President Obama goes home. He's made it clear he intends to spend time and effort on this most difficult of missions.

"John Kerry already knows everyone," remarked veteran Palestinian politician Hanan Ashrawi. "The Americans still have a chance to make peace but only if they stand up to the Israelis."

Doubts persist about the Israeli prime minister's commitment to "two states for two peoples" even though he used the same phrase when he stood next to President Obama.

Despite all the hugs and smiles this week, Mr Netanyahu did not echo Mr Obama's statement that Israel had a "true partner" for peace in Palestinian President Mahmoud Abbas and Prime Minister Salam Fayyad.

His own senior aides reject those doubts. "I have heard him say many times the same phrase as Ariel Sharon," said one official.

That phrase used by the former Israeli leader - "It is impossible to have a Jewish, democratic state and at the same time to control all of Eretz [greater] Israel" - was also cited by Mr Obama in his main speech.

"I am optimistic on the tactical level that peace talks will resume," said one Israeli official. "But I can't be sure on the strategic level, at that moment when the crunch comes."

But he added "if the American President is passing the ball to the Palestinians, they'd be mad not to take it."

Many Palestinians, including the young student Karma, pointed to President Obama's visit to Ramallah, with an honour guard and national anthems, "as a recognition of the Palestinian state".

For Avinoam, there's a different road to peace.

"Words have power," he said, "but the key word is trust and we have failed again and again to trust each other."

For all the power of an American president's words, the real force for change will come from Israelis and Palestinians.

Barack Obama knows that.

In European capitals, a debate is growing over whether to lift an EU embargo to allow military support to Syrian rebels.

But the EU's foreign policy chief, Catherine Ashton, is urging caution.

"We have to work through, very carefully, the best understanding we have of the implications" of lifting the ban, she told the annual Brussels Forum hosted by the German Marshall Fund.

"Would it stop people being killed or would it kill people faster?" she asked.

France seems to have made up its mind. "Lifting the embargo is one of the only means left to make things move politically," Foreign Minister Laurent Fabius declared last week.

UK Foreign Secretary William Hague reiterated that call on Sunday, arguing that there was "a strong case" for lifting the embargo when it comes under review in May.

"Our overall goal of a political negotiated settlement has not changed," underlined a Western diplomat.

But he pointed to the Syrian government's edge in the military balance of power, aided by Iran and Russia. "The opposition's weaker position doesn't create the right atmosphere for political negotiations."

Military support to the opposition from countries such as Qatar and Saudi Arabia had reportedly decreased earlier this year, but one informed source said more was now reaching rebel-held areas.

Britain and France are calling for an emergency meeting to discuss Europe's ban, but EU officials say the decision cannot be rushed.

"We have already loosened the embargo to allow for more aid," one senior EU official told me.

At the end of February, the EU amended sanctions to allow the supply of armoured vehicles, as well as non-lethal military equipment and technical aid to the opposition - on the understanding it would help protect civilians.

"Its not only up to us," the official emphasised. "We must consult Syria's neighbours already taking in a massive influx of refugees, who would be affected by any upsurge in violence."

There's also long been concern that more arms would "fall into the wrong hands" - in other words well organised Islamist fighters with their own agenda.

One European official spoke of a "battle" during the February meeting. But he said the issue was not raised last week when foreign ministers met Lakhdar Brahimi, the UN-Arab League envoy.

"Perhaps that was out of politeness to Brahimi who has made it clear he believes only a political solution will work," said a minister who attended the session.

Swedish Foreign Minister Carl Bildt told me why he opposes more military aid.

"There is a risk that if we focus on the military side, it could bring about a collapse of the political track," he said.

"All our energies should be focused on a negotiated solution."

Russia's ambassador to Nato, Alexander Grushko, sounded a similar warning. "Lifting the arms embargo is an invitation to stop talking," he cautioned.

He dismissed criticism that Moscow's military and financial aide was a key factor keeping President Bashar al-Assad in power.

One reliable source said "planeloads of money" printed in Russia were being flown to Syria.

Ambassador Grushko insisted that "we should all focus on Geneva".

The Geneva communique, first agreed by world powers last June, sets out in general terms the establishment of a transitional government whose members would be selected by Syrians through "mutual consent."

Discord between Moscow and Washington on how to move forward has been a major obstacle.

But Wendy Sherman, the US Under Secretary for Political affairs, told the Brussels Forum that the Geneva agreement "is still a basis for reaching a solution" to the conflict.

But she said the US was looking at "what more we need to do".

Western diplomatic sources say they believe some progress was recently made on holding very preliminary discussions between Syrian government and opposition representatives.

Even that would be a major breakthrough on the political front.

Many in the opposition reject any role for President Assad - even during a transitional period.

In Damascus earlier this year, a senior presidential aide told me they would not accept the idea of a transitional body with "full executive powers" which would effectively mean relinquishing control.

There's expected to be intense argument later on Monday in Istanbul, when the main opposition body, the Syrian National Coalition (SNC), discusses its next move.

Some members are pushing for the appointment of an interim prime minister, others for an interim government based in opposition-held areas of northern Syria where people are living in desperate conditions.

Coalition President Moaz al-Khatib is known to oppose the unilateral declaration of an interim government, fearing it would deepen divisions and impede any progress towards a transitional body which could bring about a transfer of power.

Some Western governments are also discouraging this option. They've been focusing on efforts to build local offices capable of stepping in where social services have collapsed.

As decision makers on all sides argue over the next steps, Syria's humanitarian crisis worsens by the day.

"In two to three months, our humanitarian space will shut," warned one Western aid official, who stressed that not enough aid was reaching people in areas where the government had lost control.

"Soon we won't be welcome," he regretted.

"We risk a double failure," he added, pointing to political disunity among world powers and a humanitarian operation that has let down the Syrian people.

As the third year of the conflict starts to unfold, there is no clear sign those risks - however worrisome - will be avoided.

They are being targeted.

"Childhood under fire," warns the Save the Children charity in a new report.

"A lost generation," lamented the UN children's fund Unicef on Tuesday.

"A war on childhood," regretted the War Child charity last year.

Syrian children are too young to understand the intricacies of a complex and brutal war fought in the name of their future.

But they know what childhood should feel like.

"You should tell her," insisted a young boy in a Damascus suburb when his frightened mother cautiously told me "everything is fine" not far from where soldiers manned a checkpoint.

"The helicopters attacked yesterday," he earnestly explained in a little person's voice and with a big person's courage.

"We are staying in our houses because we're really scared. We're begging them to stop."

But the war is not stopping; it is getting worse.

The latest report, from Save the Children, cites research that one in three children say they have been hit, kicked or shot at, as fighting between rebels and government forces has escalated over the past two years.

"My best friend Kholoud died right in front my eyes when we were playing," a brave 12-year-old told us last year as she fought back tears in a so-called "child-friendly space" run by War Child in northern Lebanon, home to many refugees.

"A bullet went through her cheek and came out through her neck."

Randa's own house was hit by a rocket in the city of Homs: a wall fell on her mother, father, and younger brother.

"My mother said, 'Thank God we survived.'"

But then the family fled, like millions of other Syrians.

When we visited the same neighbourhood in Homs, we found a devastated and desolate place.

Among the few families still living in the ruins, we met a woman and her young son.

Rahid gave us a shy teenage smile.

"Do you miss playing with your friends?" I asked.

He looked down at his ragged shoes.

"They're all dead," he mumbled.

For most children, there is not even the comfort of returning to the routine of school.

Unicef's latest report says one in every five schools has been destroyed, damaged or converted into a shelter.

Syria's statistics can be numbing as they continue to climb. But in all the numbers, there is a story about children.

We often hear how more than 70,000 have died.

Save the Children says three-quarters of children have experienced the death of a relative or close friend.

There are more than a million refugees - the UN says more than half of them are children, most under the age of 11.

Visit any of the many refugee camps or informal settlements now spreading in neighbouring countries at alarming rates of growth.

Children are everywhere, sometimes laughing and playing as children do, but often coughing with cold and fever, or crying.

This month I heard another story about an 11-year-old who survived a terrible war.

Her name is Babs Clarke - a British woman, now 81 - who still lives with painful memories of what is now called the worst but least known civilian disaster of the World War II.

"I was absolutely terrified," she told me as she recounted what happened on 3 March 1943 at London's Bethnal Green tube station when 173 died in a crush of people.

"I remember my father. I idolised him. He was such a big man… but on that day he cried."

Ms Clarke, and many like her, took decades to talk about their childhood pain.

Syrian children are sharing their stories now.

And the rest of the world cannot say they do not know what is happening.

It's not easy to get access to the evidence of a growing catalogue of war crimes and crimes against humanity. But seeing the grisly remains of even one massacre underscores a shocking savagery.

But Alice Walker always lives with hope.

"The more you honour truth, the more hopeful you can be," the acclaimed author and activist told me when she came into our BBC studios.

In an interview to mark a documentary about her life - Alice Walker, Beauty in Truth - she hailed the "awakening on the planet about insisting on truth as the guide".

Truth for Alice Walker was enshrined in her 1982 Pulitzer Prize winning book The Color Purple, where she wrote powerfully about a troubled young black woman fighting against a racist and patriarchal culture.

For her and many others, President Barack Obama's historic rise to the White House was a hopeful moment, but for her, an all-too-fleeting one.

"He charmed me, he held out a wonderful vision of a different way," she remarked wistfully, and then broke into a smile. "I was naive," she remarked.

"He and his family are visually beautiful," she explained. "But it's not so good to watch the continuation of policies we deeply disagree with."

She singled out the use of deadly weapons, including drone warfare, that she described as criminal.

In Alice Walker's view, the president "listens to bankers, not to us, the masses... the women, children and poets".

Do listen to my interview here with Alice Walker, a passionate poet, on Newshour on the BBC World Service.

How do we make sense of such a staggering sum?

The UN offers this guide. That's as if the entire population of Ottawa, Canada's capital, had to suddenly leave.

Or if everyone in the city of Birmingham, in the UK, was on the run.

But this deepening humanitarian crisis is not just about numbers.

"If we just discuss numbers, we miss the real story," cautioned Antonio Guterres, who heads the UN's refugee agency, the UNHCR. "Each single family is a tragedy."

In an effort to put a human face on a grave and growing tragedy, the UN tried to find a Syrian who, on this day, was about the millionth to register. They found Bushra in Lebanon.

Only 19, Bushra already has two children. She hasn't seen her husband Mohammad for a year and two months. She now lives with 14 other family members in one small room.

"We need help," she told the UNHCR. "We hope this will end so we can go home. We cannot ask for anything more."

It was an act of bravery by a teenaged mother to speak for a million.

"So many Syrians waiting to register today did not want to come forward to speak," explained UNHCR spokeswoman Melissa Fleming. "There is still so much fear."

And fear now runs deep across the region.

Syrians have been fleeing for their lives for many months, crossing borders into Jordan, Lebanon, Iraq, Turkey, even Israel.

Human flood

"Its not just the scale," Mr Guterres told me when he came into our BBC studios in London. "It's also the acceleration."

In December 2012, 3,000 were crossing every day, in January there were 5,000 daily, and by February the human flood rose to 8,000 every single day.

And those numbers only account for those who register. There's estimated to be another 3-400,000 who haven't signed up for aid, and don't live in tented camps.

Many middle-class Syrians fled their homes with some money to support themselves. But after many months, many are now destitute, forced to ask for help. Even dignity is being lost.

"If it goes on and on, month after month, can you imagine?" Mr Guterres warned, his voice trailing off as he tried to find words to describe this crisis.

"There is a risk of an explosion in the Middle East," he added a moment later.

This is a crisis hard to exaggerate. By the end of this year there could be a million refugees in Jordan alone, a country already struggling with its own economic and political tensions.

Syrians now make up 10% of Lebanon's population. There, and in other neighbours, the Syrian exodus strains already explosive political and sectarian fault lines.

When it comes to numbers in this disaster, they're even bigger for the money that's been pledged - $1.5bn was promised by the international community at a conference in Kuwait at the end of January.

"Only 25% of that money has come," says Mr Guterres. He explained that the biggest pledges came from oil rich Gulf states who traditionally bypass multilateral agencies such as the UN or the International Committee of the Red Cross and use their own charities or bilateral networks.

"Its absolutely essential right now to concentrate the funding," he emphasised diplomatically.

Worst winter

Last July we reported on the official opening of the Zaatari refugee camp in Jordan.

All it was then was a vista of white canvas tents snapping in a hot desert wind.

Now it is packed with close to 150,000 people, far more than it was ever intended to house. Zaatari camp is now bigger than the nearby city of Mafraq.

When it first opened, the UNHCR representative Andrew Harper admitted in his speech that "no-one would want to live here". I listened back to my recording to ensure I heard him right.

I heard him right and he was right. Outside the camp, Syrians told us they would prefer to die in Syria than live in a dusty tent in the searing heat of the desert.

Then in the dead of the worst winter in decades, we met children in southern Lebanon shivering in pyjamas and sandals outside their makeshift brick-and-metal shelters.

Some Syrians did return home last year. But many more now realise there is no choice anymore.

Inside Syria, after nearly two years of growing violence, more than 70,000 have died, and four million people are in urgent need of assistance.

Today, to mark another grim statistic, there was a cascade of statements from aid agencies and officials in many capitals. All of them emphasised the urgent need to respond to this refugee crisis, and find ways to end a punishing war.

Bushra was asked to speak for a million waiting for that to happen. By the time she finished speaking, the number was even greater.

With every minute that passes, there are five more Syrian refugees, but not much more hope this war will end anytime soon.

So wide are the gaps between Iran and world powers on Tehran's nuclear programme, the two sides couldn't even agree on what happened here.