US can't seal Afghan-Pakistan border

American troops are focusing on fighting Taliban militants and defending vulnerable towns on Afghan soil, as it has become practically impossible to stop insurgents from slipping across Afghanistan's vast border with Pakistan, a senior U.S. military commander said.

"To secure the border in the traditional sense" would "take an inordinate amount of resources," Army Col. Viet Luong acknowledged Tuesday. It also would require far more cooperation from the tribes inside Pakistan who often provide Taliban fighters safe passage, he said.

Other senior U.S. military officials have said they hope the Pakistan military does more to shut down Taliban hideouts. But the U.S. has denied reports that American forces are pushing to expand special operations raids inside Pakistan's tribal areas to target militants.

Luong said he is choosing to fight insurgents outside Afghan villages, where they are more vulnerable anyway.

"It's naive to say that we can stop . . . forces coming through the border," said Luong, who oversees troops in a part of eastern Afghanistan that includes the volatile Khost province and 162 miles of border.

He said troops under his command are still working to control the border. But he recently shut down one platoon-sized checkpoint known as "Combat Outpost Spera," confident that it would be more useful to protect more populated areas.

Khost province has been the site of frequent enemy attacks, including a high-profile suicide bombing at a remote CIA outpost last year.

The area's proximity to Pakistan puts it on the front lines of the U.S. fight for control in Afghanistan. Pakistan is host to the Taliban-linked Haqqani network, a militant movement based in its North Waziristan region that carries out operations in Afghanistan.

Luong said he has seen "subtle signs of hope" for Khost after the U.S. and Afghanistan stepped up operations against the Haqqani network. The number of operations and patrols increased fourfold, up to 12,000 in the past year, while the effectiveness of enemy fire has been cut in half, he estimated.

"Local atmospherics are indicating that the people of Khost are beginning to feel that security is much, much better," he said. "And more importantly, for the first time, they're feeling that the provincial government is now working for the people."

Pakistan's government is believed to give the Haqqani group some degree of freedom as a way of securing Islamist support against archrival India. Islamabad also faces other problems, including massive flooding this year and government instability. In the latest sign of trouble, a key party in Pakistan's ruling coalition said Tuesday it would quit the cabinet.

This year has been by far the deadliest in the nearly 10 years for coalition troops in Afghanistan, with 700 killed so far, according to an Associated Press count. Last year, 504 were killed.