George W. Obama: Gates orders 1400, and as many as 3000, more combat troops to Afghanistan.

WASHINGTON—Defense Secretary Robert Gates has decided to send an additional 1,400 Marine combat forces to Afghanistan, officials said, in a surprise move ahead of the spring fighting season to try to cement tentative security gains before White House-mandated troop reductions begin in July.

The Marine battalion could start arriving on the ground as early as mid-January. The forces would mostly be deployed in the south, around Kandahar, where the U.S. has concentrated troops over the past several months.

Commanders in Afghanistan and advocates of the strategy in Washington say temporarily adding front-line forces could help counter an anticipated spring offensive by Taliban militants returning from havens in neighboring Pakistan.

Commanders are examining other proposals to temporarily boost the number of combat troops in Afghanistan in addition to the Marines authorized Wednesday. If the plans are approved, the front-line fighting force could be increased in total by as many as 3,000 troops.