Late November" Generals, senior aides to President Barack Obama, defense experts and special-interest groups debate whether more U.S. forces should be sent to Afghanistan. Some push for no increase; others favor a boost of 20,000 to 40,000; and still others aim for as high as 80,000.
Dec. 1 " Obama orders 30,000 more troops for the war, saying Afghanistan can’t continue to be an incubator of global terrorism by al-Qaeda, the Taliban and other extremists. He also sets a deadline of July 2011 for U.S. forces to start withdrawing, although that’s later cast as a flexible target.
Early 2010 " The Camp Pendleton-based 1st Marine Expeditionary Force is sending units to the Taliban stronghold of Helmand province in southern Afghanistan.
April 2010 " By this time, Camp Pendleton commanders are expected to lead about 20,000 Marines in Helmand province. Their mission includes combating insurgents, providing day-to-day security, training Afghan forces and helping improve the region’s infrastructure.
http://www.signonsandiego.com/news/2010/feb/13/afghanistan-war-timeline/