A fierce autumn debate over Afghanistan began taking shape Monday as lawmakers reacted to a new military assessment of the situation on the ground and Congress began to confront the question of sending more troops to the region.

“Despite our best efforts to defeat al-Qaida and deny them sanctuary in Afghanistan and Pakistan, they remain a serious threat,— Senate Minority Leader Mitch McConnell (R-Ky.) said in a floor statement. McConnell pointed to an assessment by Gen. Stanley McChrystal, the top U.S. commander in Afghanistan, “[who] says that without adequate resources, we will fail. In my view, we should listen to that advice,— McConnell said.

McChrystal warned in a classified review of the war in Afghanistan that more forces are needed to successfully pursue a counterinsurgency strategy. The review, first reported Monday in the Washington Post, predicted the war in Afghanistan “will likely result in failure— if additional troops are not sent to the troubled region in the next year.

Senate Armed Services Chairman Carl Levin (D-Mich.) hailed McChrystal’s recommendation to focus on a new strategy for Afghanistan, but he stopped short Monday of supporting the recommendation for additional troops.

In his report, McChrystal also calls for increasing the Afghanistan army and police force by next year, a goal previously promoted by Levin.

“We should emphasize expanding the size and capability of the Afghan army and national police; providing the intelligence, surveillance and other support that Afghan forces require,— Levin said in a statement.

Meanwhile, a handful of Senate Democrats restated their call for setting a timeline for withdrawal.

“We have reached a turning point in Afghanistan as to whether we are going to formally adopt nation-building as a policy,— Sen. Jim Webb (D-Va.) said in a statement.

During a Sept. 15 Armed Services Committee hearing with Admiral Michael Mullen, chairman of the Joint Chiefs of Staff, Webb noted that “goals must also have an understandable endpoint so that we know when we are done, particularly in a military sense.—

Sen. Russ Feingold (D-Wis.), who has also called for a “flexible— timeline, said the focus on Afghanistan should be expanded to stabilize Pakistan, a nation that harbors nuclear missiles.

“Spending billions more dollars and sending thousands more troops to Afghanistan may not significantly improve conditions on the ground and may actually prove counterproductive in stabilizing Pakistan and fighting al-Qaida in the region and around the world,— Feingold warned.

In a media blitz on five Sunday talk shows, President Barack Obama refused to set a timeline for troop withdrawal in Afghanistan, saying he was still formulating the “right strategy.—

Congress is expected to confront the issue in the coming weeks, when military leaders, led by McChrystal, will likely request 40,000 additional U.S. troops.