Nevada, home to the BunnyRanch, the Bellagio and the Burning Man Festival, is an unlikely place for a radical Islamist to seek sanctuary, unless, of course, he wanted to wreak havoc in one of the US’s premier leisure destinations. But its arid mountain landscape closely mirrors Afghanistan’s, so when Marines camped in the state’s rugged Wassuk Range learn that Taliban insurgents have hidden weapons in a nearby village (even if that village is populated by Afghan refugees hired from Dallas and San Diego to impersonate real villagers), it does not require a great suspension of disbelief.

Inside a tent in a snow-dusted valley, Major Daniel Geisenhof, 41, and troops from the III Marine Expeditionary Force normally based in Okinawa, Japan, sit across a table from role players acting as allies from the Afghan National Army (ANA). Together they plan a morning raid on “Malakashay”, a mock village built nearby. Over tea and dates, Geisenhof ­listens to the Afghan commander’s plan. But Geisenhof has problems with it.

There are not enough soldiers – it is ­unclear whether the commander is concerned about scaring the villagers with larger forces, or just doesn’t have more and is ashamed to admit it. It seems he also favours an aggressive raid, while Geisenhof believes a softer approach will avoid alienating the village. “I wouldn’t say this to the commander,” Geisenhof’s interpreter, an Afghan from Dallas, suggests. “It makes him sound weak.”

For Geisenhof, a chiselled Marine with combat experience in Iraq and ­Somalia, the moment calls for humility and compromise. “This is a great plan, sir, but what if we’re ambushed?” He ­invites the commander to discuss more troops in private. A Marine supervisor nods approvingly. “One of the most important things you can do in these meetings is pimp the commander. Always let him save face, even if that means losing face yourself. His troops will see that, and they’ll both respect us more for it.”

“Everything with Afghans is a negotiation,” says another. “As Marines, that goes against everything we’ve known.” Yet this is the role – by turns mentor, ambassador and cultural neophyte – that Geisenhof and the 150 Marines training for three weeks last February outside Hawthorne, Nevada, will assume this year as advisers to the real ANA. For these final pre-deployment exercises, called Mountain Viper, 25-man ­adviser-teams manoeuvre Humvees and shoot AK-47s, bivouac in blizzard conditions, and learn the Afghan dialect of Dari and cultural idiosyncrasies such as how Afghans skin goats (“they respect the hell out of the thing,” notes one Marine).

Some 180 refugees from American-Afghan communities are paid up to $250 a day to play villagers, insurgents and soldiers, and to toss out cultural insights. Many fled to the US to escape the Taliban, and say they participate in Mountain Viper to help their motherland alleviate its 25-year burden of war. “The Soviets made a lot of mistakes,” says a refugee now living in San Diego who is playing an ANA officer. “They didn’t know our culture or our people. What the Marines are doing is very smart. Hopefully, it will save lives in Afghanistan.”

Indeed, an upturn in violence there and a resurgence of Taliban control, which US National Intelligence director Mike McConnell estimates at 10 per cent of the country, have underscored the need for more capable Afghan security forces. Last autumn, the US asked Nato countries for more forces to quell the volatile south. Meanwhile, 3,200 Marines were deployed to southern Afghanistan in March – 1,000 as ANA trainers – still below the 3,500 that General Dan K McNeill, commander of Nato’s International Security Assistance Force, has requested.

Mountain Viper is an answer to this shortfall. It is the most immersive environment the Marines have created to train its adviser teams for Afghanistan, who had previously only received ad-hoc training at regional bases. Last spring, the Marine Corps formed the Adviser Training Group to supervise the first Mountain Viper; a third is planned for this summer.

From its ­infancy in 2002, the ANA has been built into a force of 45,000. It is targeted to reach 70,000 by 2010. Despite efforts such as Mountain Viper to improve relationships with locals, Afghan president Hamid Karzai has chastised the US and Nato for inadvertent civilian casualties – resulting from aerial bombardments and botched house raids – that threaten the tenuous popular support for the Afghan government and international presence. “That has been a challenging part of everything we do,” says US Army Major General David ­Rodriguez, a commander in eastern Afghanistan. “But part of that is because of how the enemy fights and how they try to have civilians in there.”

On the morning of the raid on Malakashay, a convoy of ANA soldiers and Marines in armoured Humvees heads from base camp towards the village. Malakashay consists of a dozen small shelters with painted rock and mud façades amid the sagebrush. Chicken korma scents the air. When the pickups arrive, the Afghans jump out and descend on the houses. They seize an insurgent guarding a weapons cache and bring him to Geisenhof, who then engages in village diplomacy, or rather, damage control – shaking hands with elders, reassuring them. Later, in a tribal council with the ANA commander, villagers complain that ANA soldiers stole antique glass from a home during the raid. They ask if the Americans could donate a water pump, tractor parts, and help clear landmines.

“You have to be a creative storyteller,” a supervisor advised Marines earlier on. “If you say, ‘inshallah, we’ll get to it’, they’ll know you can’t deliver. It’s ok to dance around it. They’ll understand that you care and will look into it.” Geisenhof says he will contact the UN about clearing the mines, but avoids making promises about the parts. “I’ll check our supplies.” The convoy then leaves for base camp: ANA role players are there, busy grilling kebabs.

According to the US Department of Veteran Affairs (VA), at least 48,000 Iraq and Afghanistan veterans have been treated for drug abuse – 16 per cent of the total Iraq and Afghanistan veterans treated by the VA. “These numbers are only the tip of the iceberg; many veterans do not turn to the VA for help coping with substance abuse. Instead they rely on private programmes or avoid treatment altogether,” says Vanessa Williamson, policy director of Iraq and Afghanistan Veterans of America. The Department of Defense’s Taskforce on Mental Health reports that of the Iraq and Afghanistan veterans who accessed care between 2002 and 2007, 37 per cent were diagnosed with or evaluated for a mental disorder.

Hidden costs

1. A Harvard study found that the annual cost of treating veterans could rise to $2.3bn by 2009.
2. The US House of Representatives Veterans’ Affairs Committee found that more than 22,500 service members were discharged since 2001 on the basis of “personality disorders”, making it more difficult for those ex-soldiers to be treated by the VA.
3. According to a 2006 study by the National Alliance to End Homelessness, there are nearly 200,000 homeless veterans; 26 per cent of the overall homeless population in the US.