Claiming progress in Afghanistan, President Obama plans to announce tonight that he will withdraw 33,000 U.S. troops from the war zone by September of 2012.

Officials familiar with the president's speech said he will remove 10,000 troops this year, with 23,000 more to be withdrawn by the end of next summer on a timetable to be determined by the military.

The 33,000 troops slated for withdrawal reflects the Afghanistan deployment that Obama ordered in late 2009, at a time of military reversals to the insurgent Taliban.

In a high-profile speech at the U.S. Military Academy at West Point on Dec. 1, 2009, Obama ordered the deployment of 30,000 additional troops; he later authorized an additional 3,000 troops to give the military more flexibility.

At that time, Obama also announced he would begin a withdrawal process in July of 2011 -- the subject of tonight's speech at the White House.

The president also plans to say the withdrawals signal the beginning of the end of the war that began shortly after the terrorist attacks on Sept. 11, 2001, ordered by the al-Qaeda organization from a base in Afghanistan.

The U.S. and allies say they will turn over security responsibility to the Afghans in the year 2014.

In his speech, Obama will say that the goals of the earlier troop surge are being met, and that al-Qaeda has been severely damaged, as evidenced by the death of Osama bin Laden at the hands of U.S. special forces.

The president also plans to say that U.S. forces have reversed gains once made by the Taliban, and that Afghan security forces are improving under the training of U.S. officials.

The drawdown that Obama plans to discuss tonight would still leave 67,000 troops in Afghanistan, more than twice the number there in late 2008.

In addition to detailing the troop withdrawals to be made from Afghanistan in the following months, President Obama will try to send several messages in tonight's big speech.

Among them:

This is the beginning of the end. Obama and his aides have stressed an agreement among the United States, NATO and other allies to turn over all security operations to Afghanistan by the year 2014 -- the real deadline for the war.

"This is within a framework of the gradual transition of security lead to the Afghans," said White House spokesman Jay Carney. "It's begun already in some places, but it will progress over the next several years."

He knows that the war -- nearly 10 years old -- is increasingly unpopular. Obama may cite the financial costs of the war, especially at a time of economic uncertainty in the USA.

It will be interesting to see whether Obama mentions another controversial aspect of the war: Afghan President Hamid Karzai. U.S. lawmakers have accused Karzai's government of corruption, while Karzai has criticized U.S. military action.

He is delivering on promises made Dec. 1, 2009.

That was the night Obama announced the deployment of 30,000 more troops to Afghanistan, and outlined the following "objectives":

We must deny al-Qaeda a safe haven. We must reverse the Taliban's momentum and deny it the ability to overthrow the government. And we must strengthen the capacity of Afghanistan's security forces and government so that they can take lead responsibility for Afghanistan's future.

The war has been worth it. Obama -- a critic of the Iraq War -- has defended the action in Afghanistan, stressing that the country served as a base for al-Qaeda terrorists in the years before 9/11.

"The process was all about the mission that was laid out in December of 2009, the surge in forces that followed from that decision and that mission, and the evaluation of the success that we've had since that mission began," Carney said. "Having said that, we are always mindful of the fact that, as powerful and wealthy as this country is, we do not have infinite and unlimited resources."

There has been success. On Dec. 1, 2009, Obama ordered the deployment of 30,000 more U.S. troops to Afghanistan -- and said he would begin a withdrawal process in July of 2010.

Obama is likely to say the troop surge has been a success, all but wiping out al-Qaeda in Afghanistan.

The death of al-Qaeda leader Osama bin Laden is also likely to get a presidential mention.

"The successful mission against Osama bin Laden highlights the broader success that we have had in going after members of al-Qaeda in the Afghanistan/Pakistan region," Carney said.