Now, the top U.S. and NATO commander in Afghanistan is asking for tens of thousands more troops to stem the escalating insurgency, raising the question of how many more troops it would take to succeed.
The commander, Gen. Stanley McChrystal, says the extra forces are needed to implement a new strategy that focuses on protecting civilians and depriving the militants of popular support in a country where tribal militias may be Taliban today and farmers tomorrow.
The White House said Tuesday that President Barack Obama has nearly finished gathering information and advice on how to proceed in Afghanistan, where bombings killed eight more American troops.
With October now the deadliest month for U.S. forces in the war, many experts question the need for more troops.
"The U.S. and its allies already have ample numbers and firepower to annihilate the Taliban, if only the Taliban would cooperate by standing still and allowing us to bomb them to smithereens," said Andrew Bacevich, a professor of international relations and history at Boston University, and one-time platoon leader in Vietnam.
"But the insurgents are conducting the war in ways that do not play to (allied) strengths."
The Taliban rebels are estimated to number no more than 25,000.
Ljubomir Stojadinovic, a military analyst and guerrilla warfare expert from Serbia, said that although McChrystal's reinforcements would lift the ratio to 20-1 or more, they would prove counterproductive.