President Obama set for upbeat speech to UK parliament

Mr Obama has been stressing the "essential" nature of UK-US relations

The White House says President Barack Obama's historic speech in Westminster Hall will be the "anchor" of his whole visit.

The man, criticised by some in the past for pursuing new friends at the expense of old allies, will talk of how the world has changed, about the rise of new powers like India and China. But he'll say the transatlantic alliance is the cornerstone of global security. Not just relevant but, that word again, essential.

Of course that may be because there are many countries in Europe who largely do what America wants, and see problems through the same lens. It is a view that often comes down to the use of military force.

Mr Obama will talk a little about when he thinks intervention is justified, in terms of promoting common values.

But he won't want to come over as too worthy. This is the president of hope and change. He left Ireland in a haze of goodwill because he made them feel better about themselves and their prospects.

He'll want to be similarly upbeat in London. He'll say it has been a tough 10 years, but the future is brighter.

He'll suggest the problems of Iraq, Afghanistan, al-Qaeda and the economy may not be in the past, but that they are of the past and largely behind us. We're turning a corner, he'll say.

But with many of those problems unsolved will even the president of hope and change be able to convince us that thing are really looking better already?