A 'Monumental Mistake'? Obama Details Afghanistan Withdrawal Plan

White House Deputy National Security Advisor Tony Blinken told CNN that the price tag for keeping troops in Afghanistan next year will be about $20 billion.

"We want to complete the job that we started. And we've been on a very clear trajectory under this president to end the war responsibly. And that means as we draw down our troops, building up the Afghans to the point where they can take full responsibility for their own security and their own future. And that's exactly what we've been doing," Blinken said.

In 2012, Obama said U.S. troops would be "all out of there by 2014."

"We never signed up to be a permanent security force in Afghanistan to fight against the Taliban," a senior administration official said on background today. "And in fact, we were very clear after the review in 2009 that we were not going to set as a U.S. objective eradicating Taliban presence or influence in Afghanistan."

The announcement preceded Obama's Wednesday commencement address at West Point, where he's expected to lay out his comprehensive foreign policy vision.

Of the Afghanistan plan, House Armed Services Committee Chairman Buck McKeon (R-Calif.) noted that "holding this mission to an arbitrary egg-timer doesn’t make a lick of sense strategically."

"Does the president seek to replicate his mistakes in Iraq where he abandoned the region to chaos and failed to forge a real security partnership? We are in Afghanistan because it was the spawning ground of al-Qaeda and the devastating attack on American soil," McKeon said. "Those threats still exist. We leave when the Afghans can manage that threat, rather than on convenient political deadlines that favor poll numbers over our security."

The top Democrat on the committee, Rep. Adam Smith (D-Wash.), said he thinks the administration is "following through on its goal of responsibly reducing our active involvement in Afghanistan."

“We cannot and should not continue to maintain a large presence in Afghanistan forever, but we also cannot overlook our national security interest in the region. The announcement today demonstrates that the president understands this balance," Smith said. "…There will be other decisions to be made in the future about our assistance to the Afghan government, but the American people have paid a significant price in this conflict and it is time that we allow the Afghan people to take responsibility for their own future.”

House Intelligence Committee Chairman Mike Rogers (R-Mich.) said it's "appropriate" that Obama decided to keep some troop presence in Afghanistan beyond the end of the year.

"That being said, I question whether the policy reflected by these numbers and timelines truly confronts the threat we face," Rogers said. "Even now, an al-Qaeda safe haven is emerging in northeastern Afghanistan; and I question whether the enemy will take further advantage of the announced timeline to renew its efforts to launch new operations, as we see them attempting in Iraq and Syria today."