Menedez said all troops should be withdrawn given the recent killing of Osama bin Laden, estimates that just a few dozen al Qaeda operatives remain in Afghanistan, and the need for Afghanistan to take over more of a role in shaping its own future. He also warned that the nation-building effort the U.S. appears to be involved in would take far more commitment than the U.S. is prepared to make.

"The current threat simply does not justify the presence of a hundred thousand American troops on the ground," he said on the Senate floor, just moments before the Senate adjourned. "Not only are the costs of lives and treasure far to high, but there is a growing consensus that absent a very long and sustained commitment involving many troops on the ground, that we can't win the hearts and minds of the Afghan people.

"It is clear to me that the present course is unsustainable," he added. "It creates dependency, breeds corruption and ignores the fact that at some point Afghanistan will have to stand on its own, on its trillions of dollars of mineral deposits, and build its own future."

Menendez, a senior Democratic member of the Senate Foreign Relations Committee, had sharp criticism for Obama's counterinsurgency strategy that sent more than 30,000 more troops to Afghanistan.

"We are spending $10 billion a month on a counterinsurgency strategy in Afghanistan that does not have a clear path to a definable victory," he said. "I am not certain a counterinsurgency strategy in Afghanistan does anything but feed and grow the insurgency. In short, I am not certain that a counterinsurgency strategy is a winnable strategy."

"Our mission should be one of counterterrorism, not counterinsurgency," he concluded.