UPDATED 4:50 p.m. ET
President Obama plans to tell the nation Wednesday night his "surge" of 33,000 troops sent to Afghanistan beginning in late 2009 will be withdrawn by September of next year, administration sources told CBS News, about two months before voters decide whether he will get another four years in office.
In his sixth address to the nation, Mr. Obama is expected to say about 5,000 troops will begin coming home this summer with an additional 5,000 troops by the end of this year. And roughly 23,000 additional troops are expected leave by September, 2012, the sources said. That would still leave about 70,000 troops in Afghanistan - roughly twice as many troops as when Mr. Obama took office in January 2009.
That timetable is more aggressive than some military advisers had urged. Mr. Obama made the final decision Tuesday after weighing options presented to him by General David Petraeus, his top commander in Afghanistan.
The September 2012 withdrawal date would mean that large numbers of troops would be coming out of Afghanistan during the summer of 2012 fighting season which stretches from spring to fall. The fighting season has traditionally been the time when U.S. forces try to put maximum pressure on the Taliban and other insurgents. Executing a withdrawal in the middle of that fighting season will complicate that mission.
In the past, Mr. Obama has said that future withdrawals would depend on conditions on the ground, and it's yet to be known how much wiggle room the president will give on this timeline in his remarks tonight.
Mr. Obama is under intense pressure from many in Congress, including Senate Armed Services Committee Chairman Carl Levin (D-Mich.), to bring the troops home as quickly as possible.
Levin told reporters on Tuesday that "the notable improvement in the security situation" in Afghanistan allows "for a reduction of at least 15,000 U.S. troops by the end of this year."
House Speakerof troops from Afghanistan, though he stressed that he would back the president's decision as long as Mr. Obama listens to military and diplomatic officials dedicated to the United States' efforts in Afghanistan.
"If the president listens to the commanders on the ground and our diplomats in the region," Boehner told reporters, "I'll be there to support him."
But Boehner cautioned against an excessively steep withdrawal of troops, citing the extensive United States investments in the region.
"I'm concerned about any precipitous withdrawal of our troops that would jeopardize the success that we've made," he said, without elaborating on what would constitute a precipitous withdrawal.
A recent CBS News poll found that 64 percent of Americans want the number of troops of Afghanistan reduced, the highest number since CBS News first asked the question in 2009.
Additional reporting by CBS News national security correspondent David Martin and CBS News White House producer Chloe Arensberg