Top U.S. generals, European presidents and analysts say the blame lies to the east, in militant sanctuaries in neighboring Pakistan. As long as those areas remain havens where fighters arm, train, recruit and plot increasingly sophisticated ambushes, the Afghan war will continue to sour.
"The U.S. is now losing the war against the Taliban," Anthony Cordesman, of the Washington-based Center for Strategic and International Studies, wrote in a report Thursday. A resurgent al-Qaida, which was harbored by the Taliban in the years before the Sept. 11 attacks, could soon follow, Cordesman warned.
Cordesman called for the U.S. to treat Pakistani territory as a combat zone if Pakistan does not act. "Pakistan may officially be an ally, but much of its conduct has effectively made it a major threat to U.S. strategic interests."
An influx of Chechen, Turkish, Uzbek and Arab fighters have helped increased the Taliban's military precision, including an ambush by 100 fighters last week that killed 10 French soldiers, and a rush on a U.S. outpost last month by 200 militants that killed nine Americans.
Multi-direction attacks, flawlessly executed ambushes and increasingly powerful roadside and suicide bombs mean the U.S. and 40-nation NATO-led force will in all likelihood suffer its deadliest year in Afghanistan since the 2001 invasion.
British Prime Minister Gordon Brown, on a visit to Kabul last week, said he knows that something must "be raised with Pakistan's government, and I will continue to do so." French President Nicolas Sarkozy, who rushed to Afghanistan after the French attack, warned Thursday that "terrorism is winning."
"Military sanctuaries are expanding in the (Pakistani) tribal areas," Gen. David McKiernan, the American four-star general in charge of the 50,000-strong NATO-led force here, told The Associated Press last week. McKiernan has called for another three brigades of U.S. forces - roughly 10,000 troops - to bolster the 33,000 strong U.S. force here.
Complicating relations between the Afghan government and the U.S., last week a joint Afghan-U.S. military operation in Herat province killed around 90 civilians, President Hamid Karzai's office says. The U.S. said it was investigating.
Some 188 international soldiers have died in Afghanistan this year, including the 101 Americans, according to an Associated Press count. This year's toll is easily on track to surpass the record 222 international troop deaths in 2007.
According to Defense Department statistics released Sunday, at least 508 members of the U.S. military have died in Afghanistan, Pakistan and Uzbekistan as a result of the U.S. invasion of Afghanistan in late 2001. Of those, the military reports 362 were killed by hostile action.
U.S. critics of the Afghan government are becoming increasingly vocal. Rep. Jim Marshall, a Georgia Democrat who is a member of the House Armed Services Committee, said last week that Karzai's government "is not nearly where it should be."
"I'm not willing to have a long-term U.S. commitment, a substantial U.S. commitment to Afghanistan without seeing substantial reform and improvement in the government," Marshall said on a visit to Kabul.
Karzai's influence barely extends outside the capital. The Interior Ministry is seen as uniformly corrupt, and opium poppy cultivation has soared in recent years.
McKiernan said that "there is a sense of real frustration with the government of President Karzai. People were expecting gains over time but they aren't feeling much."
Karzai admitted in an AP interview last week that Afghanistan still lacks a properly functioning government and that corruption is rampant. He said he will run for a second term next year in hopes of addressing those problems.
The president also blamed the rise in Afghan violence directly on Afghanistan's and NATO's neglect of the sanctuaries, training grounds and financial center of the Taliban - a clear reference to Pakistan.
The U.S. is believed to have launched several missile strikes into Pakistan's tribal areas this year in an attempt to take out militant leaders. Missiles destroyed a suspected hide-out in South Waziristan, near the Afghan border, on Wednesday, killing at least five people.
Seth Jones, a RAND Corp. analyst who has studied Afghanistan for years, said Taliban militants have simply become better at war after seven years of practice against U.S. and NATO forces. Fighters, particularly militant commanders, are also using their sanctuary in Pakistan to devastating effect, he said.
"I think there's got to be a strike on the leadership structure, including Mullah Omar, Siraj Haqqani, and (Gulbuddin) Hekmatyar," who reside in Pakistan, said Jones. "As the insurgency has become more sophisticated, many of the senior leaders continue to exist, and they are one of the reasons the insurgency is getting better."
Marshall, the Democratic congressman, said Pakistan itself is feeling threatened by the increase in militancy on its soil and wants to see insurgent leaders taken out.
"You've seen the progression here," Marshall told AP. "Initially we wouldn't even fire back across the (Pakistan) border. We changed that. We're firing back. We're pursuing, and now acting on intelligence we are prepared to use discreet weaponry to take out high value targets" in Pakistan.
"They want the minimal American presence to help them do that," he said.
Rep. Chris Shays, a Republican member of the House Homeland Security committee, said it appears the United States is making some of the same mistakes in Afghanistan that it did in Iraq, such as underfunding the training of the Afghan army. He also called for an increase in the use of "soft power" like aid work and "some sort of effort in reconciliation."
"I don't pretend to know enough about how that would be involved," he said in a visit to Kabul last week, "but the bottom line is that as I look at this issue, I don't see how we can succeed on our present track."
Associated Press reporters Kathy Gannon and Rahim Faiez contributed to this report from Kabul.