Lawmakers criticized Pakistan on Thursday as an unreliable partner in the war on terrorism and one that could turn the tide of the war if it wanted.
"They don't seem to want a strategic relationship," New Jersey Democratic Sen. Bob Menendez said of the government in Islamabad. "They want the money. They want the equipment. But at the end of the day, they don't want a relationship that costs them too much."
Ain fighting the al Qaeda terrorist network, Pakistan is also a major recipient of U.S. aid. President Barack Obama and Congress recently approved a $7.5 billion aid package for economic and social programs in Pakistan in a bid to strengthen the civilian government there.
But many in Congress have grown skeptical that Islamabad is doing all it can to drive out al Qaeda forces hiding along its mountainous Afghan border. Those doubts reached a new pitch this week after Obama's30,000 more U.S. troops to Afghanistan by next fall, with the anticipation that troops would start coming home in July 2011.
Obama has not said whether or how the troop buildup would accelerate attacks on the terrorist network hiding in Pakistan. The U.S. has previously relied on drone-launched missile strikes, and those operations are classified.
"It is not clear how an expanded military effort in Afghanistan addresses the problem of Taliban and al Qaeda safe havens across the border in Pakistan," said Sen. Richard Lugar, the top Republican on the Senate Foreign Relations Committee.
Rep. Ike Skelton of Missouri, a leading conservative Democrat, saidwas the nation's best shot but Pakistan could end the war if it wanted.
"Conversely, if Pakistan were to return to old habits of supporting the Afghan Taliban, the war may be almost impossible to win," he said.
Obama has sought to assure lawmakers - and the rest of the world that he sees Pakistan inextricably linked to Afghanistan. In his speech on Tuesday, the president said both governments were "endangered" because of al Qaeda.
"The stakes are even higher within a nuclear-armed Pakistan, because we know that al Qaeda and other extremists seek nuclear weapons, and we have every reason to believe that they would use them," he said in his speech from West Point.
Testifying for the second day on Obama's new war plan, the president's chief military and diplomatic advisers said Pakistan was a critical component of the strategy.
"We have a lot of work to do in trying to convince them that we're not trying to take over their country, that we're not trying to take control of their nuclear weapons, and that we are actually interested in a long-term partnership with them," said Defense Secretary Robert Gates.
Several Democrats, including Menendez and Sen. Russ Feingold of Wisconsin, have threatened to withhold their support for more money for the war, although lawmakers said it was unlikely that Congress would try to block the deployments. Instead, members from both parties say they want to find a way to pay for the troop increase that won't add to the deficit.
In a press conference Thursday, House Speaker Nancy Pelosi said she did not support a proposal by Wisconsin Democratic Rep. David Obey that would have imposed a war tax on most Americans.
Pelosi, D-Calif., said the first step should be an all-hands briefing to Congress by Obama's top advisers.
"We have to handle it with care, listen to what they present, and then members will make their decision," she said.
The results of the billions in U.S. aid to Pakistan have been mixed. While the army has taken on the Pakistani Taliban, it has failed to go after Afghan Taliban leaders who base their operations in the tribal areas in the border region. At the same time, anti-Western sentiment in Pakistan has grown.
Many Western officials and analysts believe Pakistan is playing off both sides - accepting U.S. money to crack down on militants while tolerating the Afghan Taliban in case the radical Islamic movement gains control in Afghanistan once the American troops withdraw.
Officials estimate there are 500 al Qaeda fighters and 50,000 Taliban militants in Afghanistan and Pakistan.
For its part, Pakistan has been cautious in its response to Obama's plan. In London on Thursday, Prime Minister Yousuf Raza Gilani declined to endorse the U.S.-led troop increase and said his government needs more information.
Gates said he initially opposed the idea of a troop increase because he feared it would make the U.S. footprint in Afghanistan too heavy. He said he also was hesitant to set a timeline on when troop withdrawals would begin.
He said he was ultimately convinced by Gen. Stanley McChrystal, the top U.S. commander in Afghanistan, that the size of the force was less important than the mission troops would be given. His colleagues also convinced him that setting a date to start withdrawals would help encourage the Afghans to take more responsibility.
Secretary of State Hillary Rodham Clinton on Friday will take the administration's case for escalating the war to NATO's top council, where McChrystal will attend a foreign ministers meeting. Clinton said she expects the allies to makein the 5,000 to 7,000 range.