WASHINGTON- President Barack Obama will unveil his new strategy for the war in Afghanistan in a prime-time televised speech on Tuesday. But in the hours beforehand, officials offered a preview of what he will tell Americans, who are sharply divided over the war.

WHAT IS THE AIM OF THE NEW STRATEGY?

Much the same as the Obama administration's first Afghanistan strategy announced last March -- to dismantle, disrupt and defeat al Qaeda, the Islamist militant group that operates in Afghanistan and neighboring Pakistan and carried out the September 11, 2001, attacks on the United States.

But in previewing what the president will say, a senior administration official added the word ultimately, as in ultimately defeat al Qaeda. If Obama repeats that phrase, it would be notable as it gives him some wiggle room that would allow him to pull troops out sooner rather than later.

Obama will emphasize that the goal of U.S. forces will be to prevent the return of al Qaeda to Afghanistan, reverse the momentum of the Taliban, especially in the south and east of the country, and to stop the Taliban from overthrowing the Afghan government.

U.S. troops will also help to secure key population centers, a key recommendation by Obama's top general in Afghanistan, General Stanley McChrystal, in his August assessment that a classic counterinsurgency campaign was needed to arrest the deteriorating security situation.

U.S. forces will also accelerate training of Afghan security forces so that they can hand over control to them as soon as possible. To achieve this goal, Obama has ordered that all U.S. combat units be partnered with an Afghan unit, echoing a similar strategy by U.S. forces in Iraq.

The strategy also aims to deliver political, economic and military aid to Pakistan, whose government faces a growing threat from the Taliban and al Qaeda on its soil.

HOW DOES HE PLAN TO ACHIEVE THIS STRATEGY?

U.S. officials said Obama would announce a surge of 30,000 more U.S. troops to Afghanistan and that their deployment will be completed by the summer of 2010. That's less than the 40,000 McChrystal wanted, but it will still bring the total number of U.S. forces in Afghanistan to 100,000.

The officials said they expected NATO, whose member states have about 40,000 troops in Afghanistan, to announce on Friday that the alliance plans to commit more troops to the war.

U.S. officials have been critical of some NATO members' reluctance to increase troop numbers and commit them to dangerous theaters of the war, which is unpopular in Europe.

NATO members largely rebuffed requests by the former Bush administration for more troops, so any increase in numbers would be a political success for Obama, who has sought to rebuild strained relations with Europe.

Obama will also expand the civilian element of the strategy, and will say that civilians are key to moving beyond Kabul in a bottom-up approach to improve governance and develop capacity in the provinces. Afghan President Hamid Karzai's government has been criticized for corruption and failing to deliver basic services.

WILL OBAMA SKETCH AN EXIT STRATEGY?

No, but he will go some way in trying to reassure skeptical fellow Democrats and an American public weary of eight years of war. The officials said he planned to begin withdrawing U.S. troops in July 2011.
He would also set a date for the start of the transfer of security control from NATO to Afghan security forces but would not give an end date or say at what pace it would proceed.

As in Iraq, where U.S. troops took many months to complete the transfer of security to Iraqi forces, the pace will be determined by events on the ground. In Iraq, the timetable for the handover of provinces was often derailed by violence.

The president will make a strong point tonight that this is not an open-ended commitment. And the idea here is that all of us have to have a sense of urgency about this opportunity in the coming months to shift the momentum in Afghanistan, one official said.

The official appeared to suggest, however, that U.S. troops could be in Afghanistan for some time.

While we do not intend -- and the president will make this very clear tonight -- to commit American combat forces indefinitely to Afghanistan, we do reaffirm our long-term strategic partnership with Afghanistan, but not at anything like 100,000 U.S. troops in their country, the official said.

(Additional reporting by Jeff Mason, Patricia Zengerle and Matt Spetalnick; editing by Patricia Wilson and Eric Beech)