Updated at 12:29 p.m. EST
President Barack Obama's planned troop buildup in Afghanistan came in for more skepticism on Capitol Hill Thursday with lawmakers zeroing in on how the U.S. will deal with terrorist havens in neighboring Pakistan.
"What happens in Pakistan ... will do more to determine the outcome in Afghanistan than any increase in troops or shift in strategy," said Sen. John Kerry, chairman of the Senate Foreign Relations Committee.
Mr. Obama has depicted the effort to defeat al Qaeda as the center of his war strategy, but his national address Tuesday contained no details on how he planned to accelerate attacks on the terror network. The U.S. has relied largely on drone-launched missile strikes in recent months, and those operations are classified.
Opening a hearing on Afghan strategy, Kerry, D-Mass., said that it is the "presence of al Qaeda in Pakistan, its direct ties to and support from the Taliban in Afghanistan and the perils of an unstable, nuclear-armed Pakistan that drive our mission,"
Sen. Richard Lugar, the committee's ranking Republican, chimed in, saying the president and his administration "must justify their plan not only on the basis of how it will affect Afghanistan, but also on how it will impact our efforts to promote a much stronger alliance with Pakistan."
Lugar said "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."
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It was the second day of hearings into Mr. Obama's plan to the largest expansion of the war since it began eight years ago. As with before other lawmakers, the committee was questioning Secretary of State Hillary Rodham Clinton, Defense Secretary Robert Gates and Chairman of the Joint Chiefs of Staff Adm. Mike Mullen.
Mullen used his opening remarks to assure Kerry and Lugar that the administration's strategy takes Pakistan into account. "The linkage between Pakistan and Afghanistan is almost an absolute," Mullen said.
"A stable, supportive Afghanistan will make a big difference on how Pakistan sees its future," he said.
Both Gates and Mullen sought to underscore the threat that al Qaeda poses in Pakistan, which maintains its own arsenal of nuclear weapons.
Gates said he considered the dangers to be greater than they were 18 months ago because al Qaeda has become "deeply involved" with Taliban forces operating inside Pakistan that are trying to destabilize the government there.
Mullen said al Qaeda's pursuit of nuclear weapons and interest in Pakistan is "extraordinarily dangerous."
Kerry said he believes Pakistan cooperation is vital and that the administration needs to do a better job making that case.
Democrat Robert Menendez of New Jersey gave one of the most spirited arguments against the troop buildup.
"I just don't get the sense at this point in time that there is a comprehensive policy that says that I should vote for billions of dollars more to send our sons and daughters in harm's way in a way that we will ultimately succeed in our national security," Menendez said.
One particular problem is Pakistan, he added.
"They don't seem to want a strategic relationship. 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," Menendez said.
He referred to military and nonmilitary aid to Pakistan. Congress has approved spending $1.5 billion a year over five years mainly on economic and social programs there. Since 2001, the U.S. also has given the Pakistani army billions of dollars so it will help in the counterterror war.
The results 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. funds to crack down on Pakistani militants while tolerating the Afghan Taliban in the expectation that the radical Islamic movement will take power in Afghanistan once the Americans withdraw.
In London on Thursday, Prime Minister Yousuf Raza Gilani signaled his country's cautious response to Obama's new policy by declining to endorse the U.S.-led troop surge. Gilani said his government needs more information about Obama's plan.
Despite misgivings by U.S. lawmakers to various parts of Obama's plan, members of Congress seem poised to back the president's plan, which encountered only tepid criticism Wednesday in the Senate Armed Services and House Foreign Affairs committees.
Critics conceded that Obama will have little trouble early next year getting Congress to provide an added $30 billion or $40 billion to carry it out.
After her morning testimony, Clinton will take the administration's case for escalating the war to NATO's top council on Friday. She will meet with allied foreign ministers, plus representatives of other countries that have troops in Afghanistan, and the allied ministers will hold a separate session with Russian officials.
Clinton told congressional committees this week that she expects the allies to make new troop contributions, but it's not yet clear how many will be offered, or how soon.
Gen. Stanley McChrystal, the top commander of U.S. and NATO troops in Afghanistan, is to attend the foreign ministers meeting Friday to lay out in detail the military plan.