If countries were rated on how tough it is to fight wars on their soil, Afghanistan would come close to the top of the list.

Landlocked, with an extreme climate and paralyzing dust storms, it’s also bordered by dizzying mountains and safe highways are sparse.

That’s why escalating militant attacks on NATO fuel trucks heading from Pakistan to Afghanistan — the most recent on Monday — are a sign that the war against the Taliban is limping badly, if not hobbled. And they show the scarcity of supply line options may be a decisive factor in how and when the conflict concludes.

“The U.S. has tried to develop the northern distribution system, but the heavy duty supplies still have to go through Pakistan,” says Shuja Nawaz, director of the Atlantic Council’s South Asia Center in Washington. “Given the short timetable the coalition is operating on, the chances of finding an alternative are dim.”

Between 75 and 80 per cent of NATO supplies are trucked from the Pakistani port of Karachi through the forbidding Khyber Pass and into Afghanistan. The most crucial is fuel. But they include vital items from water to weapons.

The pass has been shut down several times, and after a helicopter fired on and killed three Pakistani frontier troops last week Pakistan blocked the supply lines. It had complained earlier of similar cross-border attacks.

For NATO, the route has been dogged by years of mayhem and uncertainty.

“We accept responsibility for the attacks on the NATO supply trucks and tankers,” spokesman Azam Tariq of the Tehreek-e-Taliban Pakistan told reporters Monday. “We will carry out more such attacks in future. We will not allow the use of Pakistani soil as a supply route for NATO troops based in Afghanistan.”

The U.S. is well aware of the dilemma and has been expanding its use of an air base in Kyrgyzstan to deliver troops and supplies to Afghanistan’s battlefields. But there have been ongoing disputes with the Central Asian country over rental fees, and a coup earlier this year put its stability in doubt.

Possible overland alternatives include a route through Georgia, Azerbaijan and Turkmenistan, inviting a diplomatic wrangle with Russia, which is wary of American influence on its former possessions.

“We are pretty much stuck with Pakistan,” says Thomas Johnson of the Naval Postgraduate School in Monterey, who has advised the Canadian and U.S. governments. “The Central Asian states are completely landlocked. It is a very dire situation.”

The dependence on Pakistan includes more than geography, says Ontario-based defence analyst Sunil Ram of the American Military University.

“About 80 per cent of (NATO) fuel requirements are from refineries in Karachi,” he said. “It’s strategically easy for the Taliban to stop the convoys. Even if they cut off 15 to 20 per cent of the fuel it has a large impact on the war because it reduces the ability to operate.”

And, he points out, a number of international media reports contend the U.S. has reverted to paying the Taliban to stay away from the convoys.

Washington is also at odds with Pakistan over Islamabad’s responsibility for quelling the Taliban on its territory, although the dispute has diminished since massive floods hit the country and the army was deployed to aid displaced civilians.

“There are 70,000 troops deployed in flood relief, and 150,000 are in locations in the northwest and along the (Afghan) border,” said Nawaz. “But it’s still not enough to protect convoys going up from Karachi. The danger used to be when they approached the Khyber Pass. Now it’s starting from Karachi. The local Taliban has affiliates all over.”

Afghanistan itself may be working on a solution. Officials there “want to create a state-run military brigade equipped with its own trucks and thousands of soldiers to carry essential NATO supplies around the country,” said a report by McClatchy Newspapers.

But there is skepticism that Afghanistan, often at odds with neighbouring Pakistan, would be able to deal with the “highway barons” who control the roads and demand protection money — both at home and across the border.