Faced with an escalating insurgency, Pakistan increasingly views U.S. efforts to stabilize neighboring Afghanistan as critical to its own security _ but is worried enough about the chances of American failure that it continues to hedge its bets.
That skepticism represents a key obstacle for Washington's emerging Afghan strategy, which envisages Pakistan targeting Taliban and al-Qaida-linked militants using its territory to launch cross-border attacks against Western forces in Afghanistan.
The U.S. sent national security adviser Gen. James L. Jones to Pakistan last week to make that point as the Obama administration nears the end of a months long debate over military proposals to send 10,000 to 40,000 additional troops to Afghanistan next year.
Analysts said they believe the Pakistani government supports an increase in troops but has been wary to say so publicly because of anti-American sentiment in the country. Some commanders also fear a surge could push militants into Pakistan, adding to its troubles.
At the same time, doubts about U.S. commitment in Afghanistan and prospects for success have made Pakistan reluctant to attack Afghan militants who could serve as useful proxies if the U.S. fails to stabilize the country and chooses to withdraw.
President Barack Obama's lengthy deliberation over U.S. strategy in Afghanistan has only increased worries in Pakistan that Washington is not committed to the fight and is more concerned about finding the quickest way out, analysts said.
"I think it is very dangerous to start talking about exit strategies at this particular point in time when the West is seen to be losing and the perception is the Taliban is winning," said Ahmed Rashid, an expert on the Taliban who has advised Obama on Afghanistan and Pakistan.
"It certainly sets the ball rolling in the region with the neighboring countries all jockeying for position with their proxies in Afghanistan as they did in the '90s," he said.
Pakistan helped nurture a generation of Islamic militants after the Soviet Union invaded Afghanistan in 1979. Following the Soviet withdrawal a decade later, Pakistan helped the Taliban seize control. Many of these militants fled to Pakistan after the U.S.-led invasion of Afghanistan in late 2001.
The U.S. is telling Pakistan that its cooperation is even more important now since portions of the emerging strategy call for a squeeze play by American and Pakistani forces on either side of the mountainous border, said U.S. officials.
Washington wants Pakistan to target the al-Qaida-linked network run by Jalaluddin Haqqani that launches attacks against U.S. forces in eastern Afghanistan from the Waziristan tribal region in Pakistan, said U.S. military officials. The U.S. would step up bombing against the militants on the Afghan side of the border, they said.
The U.S. officials spoke on condition of anonymity because the plan has not been finalized.
Even if Pakistan decides to target militants launching attacks in Afghanistan, it may lack the capacity because its resources are tied up in a major offensive against Taliban fighters in South Waziristan, said Hasan Askari Rizvi, author of several books about Pakistan's military. The South Waziristan militants have declared war on the Pakistani government.
The Pakistani army cut deals with two powerful, anti-U.S. tribal chiefs in Waziristan to remain neutral during the offensive, launched in mid-October. Both allow their lands to be used by fighters who cross into Afghanistan and are loyal to Mullah Omar, the head of the Afghan Taliban.
Militants have responded to the South Waziristan offensive by unleashing a wave of terror attacks that have killed more than 300 people.
In the latest attack, a suicide bomber blew himself up outside a courthouse in the northwestern city of Peshawar on Thursday, killing 19 people.
The spike in violence has caused more of the Pakistani public to turn against the extremists and has boosted support for the military's operations.
It has also convinced many government officials that U.S. failure in Afghanistan could be detrimental to the country's internal security, said Mahmud Shah, a former chief of the semiautonomous tribal areas near the Afghan border.
"A stable Afghanistan is in the interest of Pakistan," said Shah.
A U.S. withdrawal could lead the Taliban to take over most of southern and eastern Afghanistan near the Pakistani border, said defense analyst Talat Masood. The militant group already controls large parts of the area, but the absence of U.S. forces would allow them to expand their reach and operate relatively unhindered, he said.
"You would in fact be handing Afghanistan over to the Taliban," said Masood.
Although some militants might be sympathetic to the Pakistani government, others could use the area to stage cross-border attacks in Pakistan.
"It would be very difficult for Pakistan to then fight against its own extremist elements or Taliban because they will always find Afghanistan as a sanctuary," said Masood.
Privately, some Pakistani officials say the U.S. will have to pour in more troops and suffer more casualties if it wants to win the war.
At the same time, Pakistani officials have voiced concern that additional U.S. troops sent to southern Afghanistan could force militants to cross into Pakistan's tribal areas and southwestern Baluchistan province.
"If there are more troops in Afghanistan, how do you address the potentially greater influx into Pakistan?" said presidential spokesman Farhatullah Babar.
Also, U.S. plans to close remote posts near the border and instead focus on larger population centers in Afghanistan have sparked fears that militants will now find it easier to move between the two countries.
Pakistani officials and analysts believe the U.S. has an obligation to work closely with the government to prevent large numbers of militants from crossing into Pakistan _ the converse of what Washington has been asking of Islamabad for years.
"There has to be a joint approach and a joint vision," said Masood, the defense analyst.
However, even if the U.S. sends more troops, Masood doubts Washington will be able to persuade Pakistan to target groups like the Haqqani network because of lingering skepticism that the new strategy would succeed. He suggested the U.S. should instead enlist Pakistan's help in negotiating with these groups _ a strategy the U.S. has rejected.
"Afghans are known to change sides," said Masood. "Why can't we use Haqqani to go against the Taliban instead of being the great pillar of strength for the Taliban?"
Associated Press writer Anne Gearan contributed to this report from Washington.