Why would Obama speed the Afghan deployment?

WASHINGTON - President Barack Obama will unveil plans on Tuesday to send some 30,000 more U.S. troops to Afghanistan over six months, a senior administration official said, an escalation he hopes will permit a quicker U.S. exit.

The six-month time frame is significantly faster than the 12-to-18 month rollout that Pentagon officials had expected.

Here are some questions and answers about the time frame:

WHY THE RUSH?

Increasing the total number of U.S. troops to 100,000 by late May or early June, from about 68,000 now, is intended to provide a quick and powerful counterpunch as a resurgent Taliban gains ground in Afghanistan.

Analysts said it made sense to get more troops in quickly to be ready for the traditional Afghan fighting season.

On the military side of things, sooner is always better than later. The later you get around to clearing parts of Afghanistan the tighter a hold the Taliban will have secured over that area, said Stephen Biddle, senior fellow at the Council on Foreign Relations think tank.

The White House must also change the Taliban's perception that it is winning the war if Washington hopes to fragment the Taliban and to peel fighters away from its militant core and from al Qaeda, he added.

You are not going to make any significant headway until and unless you can convince the Taliban the trajectory of the war has changed and isn't in their favor any longer, Biddle said. A quick reinforcement is likelier to change their perception than a slow one.

CAN THE PENTAGON SEND SO MANY TROOPS IN SUCH A SHORT TIME?

U.S. Department of Defense officials were surprised by administration estimates that the 30,000 additional troops would be deployed within six months but said it could be done.

They had been planning for a more gradual, 12-to-18 month rollout that would give Obama the flexibility to adjust force levels before all of the troops arrive.

It's not impossible, one senior Pentagon official said of sending that many more by the end of May or early June. But I'm not sure that's how McChrystal is going to manage this flow, he added, referring to General Stanley McChrystal, the top U.S. and NATO commander in Afghanistan.

The more than 20,000 additional troops sent to Iraq during the surge by Obama's predecessor, George W. Bush, arrived there between January and July 2007.

McChrystal in August said the United States and its allies had 12 months to turn things around or risk failure. A six-month deployment would fall within that time frame.

Failure to gain the initiative and reverse insurgent momentum in the near-term (next 12 months) -- while Afghan security capacity matures -- risks an outcome where defeating the insurgency is no longer possible, McChrystal said.
IS THE CALENDAR DRIVEN BY U.S. POLITICS?

By setting a June deadline to get the additional troops in place, Obama could have a slightly clearer picture of whether his new strategy is working before congressional midterm elections in November. The Afghan war -- especially if it is not going well -- could be a major factor in those elections, particularly if the economy is also still in trouble.

By staggering the deployments over a longer period, Obama could have been accused of not giving his military commanders the resources they needed quickly enough and fueled criticism from Republicans.

However, experts argued Obama was likely looking at the bigger picture, rather than at next year's election.

You cannot predict in any sense if this is going to have a good or negative impact on the election. You can guess all you want but you have no way of knowing, said Anthony Cordesman, senior fellow at the Center for Strategic and International Studies think tank in Washington.

The president is probably more concerned with a second term and history than trying to time a war to the uncertainties of a congressional election ... presidents are not congressmen, he added.

DOES THIS MEAN LOSS OF LEVERAGE OVER KARZAI?

Some experts had expected Obama to use a staggered deployment to put pressure on Afghan President Hamid Karzai's weak government to do a better job. However, this approach was seen as dangerous by some analysts who believe that U.S. troop deployments should not be tied to Karzai's performance.

(Additional reporting by Alister Bull, Sue Pleming and Adam Entous; Editing by Arshad Mohammed and Eric Beech)