Rain clouds hug the rocky peaks of Afghanistan and Pakistan as a few cars and some bony cows brave the gloom and head to a small valley stream marking the border between the neighbours.
Afghan Border Police (ABP) watch the travellers pass to the official checkpoint. No passports are produced. A vehicle may be stopped if guards are suspicious, but surveillance of this frontier relies heavily on local ties.
“My soldiers... they know their people, who lives in their village. So they know the ones who are bad,” said Captain Mahmoud Qasim, who is in charge of the Dokalam border post in Afghanistan’s remote northeastern Kunar province.
On the other side of the stream is Pakistan’s North West Frontier Province, where Washington and its Western allies allege Al-Qaeda and Taliban militants are holed up, plotting new terror attacks.
But Qasim is unconcerned. Islamist extremists would not cross at an official border point, he says, but would rather infiltrate somewhere else along Pakistan and Afghanistan’s porous and ill-defined 2,500-kilometre (1,500-mile) border.
This hostile frontier landscape is one of the places where the United States says Taliban-linked insurgents are slipping into Afghanistan, staging an escalating campaign of bloody attacks on government targets and foreign troops.
US President Barack Obama, unveiling his new strategy to turn around the Afghan war, put Pakistan at the heart of the fight to defeat Al-Qaeda and vowed to boost US aid and assistance to the nuclear-armed Muslim nation.
Obama also pledged to train and increase the size of the Afghan security forces, whose jobs include policing the vast frontier of towering mountain passes impenetrable for much of the year.
But the plan faces huge challenges, especially in a country known as the “graveyard of empires” and one which has bogged down US troops since the 2001 invasion overthrew the Taliban government.
“The biggest problem that we have to date is probably the same problem that every army has had in this area for hundreds or even thousands of years,” said Captain Paul Roberts, who oversees US forces in Kunar’s Naray district.
“That is the terrain,” he said. “More troops would always be welcome and helpful, just because of the nature of the terrain.”
Obama has pledged to send 17,000 US troops into Afghanistan on top of the 62,000 international soldiers already deployed in the NATO-led International Security Assistance Force (ISAF).
Most of the US reinforcements are headed to the south which, along with eastern Afghanistan, sees the most violence.
He also announced 4,000 extra soldiers to train the Afghan security forces.
Roberts said Obama’s plans to develop the Pakistan security forces “will pay dividends”, but said improved contacts between coalition forces and Pakistan’s military were also crucial.
“If we were talking to the Pakistan military and they were effective, then really we could shut down a lot of these places that these militants are crossing over,” he told AFP.
“It does seem to me like there is not a lot of resistance to the fighters moving from Pakistan into Afghanistan,” Roberts added.
“Maybe they are overwhelmed. Maybe they have as many problems with the terrain as we do. And I think a lot of it is the culture, I think they are a lot more tied into the culture of the militants than we might want to think about.”
Sergeant Gilbert Gonzales, who works for the US military collecting data on militant tactics, said his research had shown that foreign fighters were among insurgents operating on the Pakistan-Afghanistan border.
“He (Obama) has got some good ideas. I think it will work, coming at it from that side of the border,” said Gonzales, nodding at a Pakistani mountain a few kilometres (miles) away from ISAF’s Camp Bostick in northern Kunar.
“He is thinking outside the box and trying a different approach to what we have seen in the past. I’m not sure that will end the war but it is a step in the right direction.”
Right now, said Roberts, training an effective and efficient ABP and swelling their ranks was a key step to stemming the flow of insurgents.
At the rain-sodden Dokalam checkpoint, Qasim says he too wants more troops, but no word on new hiring has come from the Afghan government, so he continues to rely on his soldiers’ instincts.
“It is very much a buddy system, which is not a very effective way of policing a border,” said Roberts. “But that’s their culture, that’s the way they do it."