How soon is too soon to make movies about a war?

Lone Survivor portrays a US mission in Afghanistan

Two new movies - The Patrol and Lone Survivor - are set against the backdrop of the Afghanistan War, but is it too soon for drama to reflect the realities of the conflict?

When people imagine what it was like to land on Omaha Beach on D-Day, what do they think of?

The odds are that most remember the opening of Saving Private Ryan (1998) - men wracked by seasickness, many cut down before they could even get out of the water, blood washing the shoreline and open-mouthed agony as limbs were blown off.

When people think of what it was like to be a "grunt", an ordinary American infantryman in the Vietnam War, what do they think of? Perhaps they think of Private Chris Taylor, played by Charlie Sheen, descending into a jungle hell in Platoon (1986).

War movies shape the way we see wars.

Gillo Pontecorvo's The Battle of Algiers (1966) is a gritty, intense portrayal of French operations against militants in the warren-like streets of the Casbah at the height of the Algerian War. The film was reportedly shown at the Pentagon at the beginning of the Iraq War in order to stimulate debate.

Saving Private Ryan (1998) recreated the WW2 Normandy landings

There's always a question over how long it takes for war films to capture the essence of a conflict.

"When it comes to fiction, to film and movies, you can say generally those done very close to the war, or shortly afterwards in the case of WW2, look very different to later depictions," says Dr Peter Busch, of King's College London's Department of War Studies and author of All the Way with JFK: Britain and the Vietnam War.

The reasons are part practical. Film-makers planning to be realistic and critical face obstacles - the military may choose not to co-operate over technical advice and the provision of materiel. But there are other sensitivities.

"In the UK we have a very strong tradition of supporting our military," says The Patrol's director and writer Tom Petch. "Can you question the policy and the strategy while our soldiers are still dying and putting their lives on the line?"

The Patrol and Lone Survivor have reached cinemas shortly before the planned US and UK withdrawal from Afghanistan after nearly 13 years of fighting. Lone Survivor, already a success at the box office, tells the true story of a failed US mission against a militant leader. The Patrol, not based on real events, focuses on British soldiers struggling to fight the Taliban in Helmand province.

The Patrol (2014) looks at the Afghanistan conflict from the perspective of British forces

"The Patrol is about seven men, a small number of people under pressure," says Petch, himself an officer in the Army from 1989 to 1997. "The soldiers wonder: 'What are we doing here?'"

Timing is key. How many of the best and most realistic WW2 movies were made before 1945? Inevitably, the tendency towards boosting morale and propaganda dominates.

After 50 years had passed, Saving Private Ryan was able to show D-Day as it was, something that would have been "unthinkable in the 1950s or 1960s", says Busch. Though it was filmed docudrama-style, blockbuster The Longest Day (1962) didn't come close to portraying the brutal reality of the landings. "Changed attitudes towards war allowed us to show the horrible side and not to glorify it."

In the fullness of time, the viewer wants to have assumptions challenged. Even just a decade after WW1, All Quiet On The Western Front (1930) captured the horror of the conflict, but proved controversial in Germany. And four decades after the war, Stanley Kubrick's Paths of Glory (1957), which depicts the trial of men accused of refusing orders to launch a suicidal attack, was criticised in France.

With the passage of time, viewers can even enjoy films told from the "enemy" perspective.

Das Boot (1981), the hours-long claustrophobic submarine epic, was a German production that rapidly became a cult classic outside Germany. Its sympathetic portrayal of the German U-boat crew might not have been appreciated in the US or UK in quite the same way in the 1950s or even 1960s when the memories of submarine warfare were still fresh.

But many movies made during wartime have not stood the test of time. Take Green Berets from 1968. Star John Wayne strongly supported the Vietnam War.

"It is a propaganda film. Very one sided. You get a very distorted view of what the war was about," says Busch.

Wayne was angry at the anti-war movement and was able to enlist the support of the US military.

"Hollywood didn't want to go near the Vietnam War because it was so controversial. Green Berets got made because John Wayne had this tremendous clout," says John Hellmann, of Ohio State University and author of American Myth and the Legacy of Vietnam.

The Green Berets (1968) was uncritical in its support for the Vietnam War

Although successful at the box office it was ridiculed by critics.

The movies that came a few years after the war fared better. Francis Ford Coppola's Apocalypse Now, with its portrayal of a disaffected special operative, a conniving and duplicitous military hierarchy and apathetic servicemen bewildered by the maelstrom they have been thrown into, remains venerated by movie buffs.

There was also Michael Cimino's Oscar-winning The Deer Hunter (1978), and Hal Ashby's Coming Home (1978), about the rehabilitation of a disabled veteran. Less high-profile examples included Go Tell The Spartans (1978), about the futile defence of an outpost, and Who'll Stop the Rain (1978), dealing with a conspiracy to traffick heroin back to the US.

Another crop in the late 1980s - Platoon, Full Metal Jacket (1987), Hamburger Hill (1987) and Good Morning, Vietnam (1987) - were all broadly anti-war.

"Platoon got a huge reception," says Hellmann. "It seemed like now we are finally getting a film that seems realistic about the 'gruntside experience' of the war."

But these films were still missing something.

"[In the films], it was bad because of how hard it was for the American troops," says Marc DiPaolo, author of War, Politics and Superheroes. "There was very little attention paid to how much damage was done to the Vietnamese."

Today, it does seem to be possible for film-makers to be brutal and realistic before the conflict is over. The Hurt Locker (2008), which won several Oscars for its portrayal of US bomb disposal experts in Iraq, was downbeat and intense, but was released during a period of optimism about the war in the wake of the 2007 surge in troop numbers. Paul Greengrass's Green Zone (2010) was well-received by critics but fared less well at the box office.

Colin Firth in Tumbledown, one of the few dramas set in the Falklands War

Some wars generate very few films. The Falklands War only produced a handful - a few BBC dramas, Tumbledown, An Ungentlemanly Act and The Falklands Play, and the Argentine film Blessed by Fire among them. The Gulf War has also produced very few - the heist drama Three Kings (1999) and Jarhead (2005) are perhaps the only notable examples. But it could be argued that neither war was an epoch-defining event in the way that the Vietnam War was.

And the movies do shape perception for later generations. "That is where students are getting their vivid image of what the Vietnam War was about," says Hellmann.

Find out more on why the Battle of the Somme film was bigger than Star Wars and the World War One Centenary.

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