Late last month, United States and NATO forces watched as Gen. John Campbell rolled up the green and white flag of the International Security Assistance Force, a symbolic gesture that represented the end of America’s 13-year combat mission of peacekeeping and reconstruction in Afghanistan.

Calling it the longest war in American history, President Barack Obama said that the ISAF was coming to a “responsible conclusion.” After spending nearly $1 trillion on the effort, many Americans are relieved the U.S. armed forces are pulling out, while others argue the U.S. is leaving Afghanistan at a particularly weak moment.

At December’s small ceremony in Kabul, Campbell expanded upon the president’s words, saying that the day marked “the end of an era and beginning of a new one.” He then unfurled another green flag of the new U.S.-led mission, called “Resolute Support.”

Despite a drawdown of U.S. troops, America’s military presence in the war-torn country wasn’t over. About 18,000 foreign troops — nearly 11,000 of them American — will remain in Afghanistan to advise and assist the country’s security forces and help them counter insurgent attacks, which have increased in recent months. 2014 was the war’s deadliest year, with Taliban attacks claiming more than 4,500 Afghan soldiers’ lives.

Going forward, “Resolute Support” is meant to be a two-year mission of shrinking support. The U.S. has planned on halving the number of troops to 5,000 by the end of 2015 and then reducing to a “normal” embassy presence in Kabul by 2016.

At its peak, the number of U.S. troops in Afghanistan swelled to 140,000 in 2010 when Obama ordered a “surge” to counter the growing insurgency. Now, the U.S. is tasked in dismantling its operations throughout Afghanistan to house the incoming foreign troops chosen for “Resolute Support.”

Reuters’ Lucas Jackson photographed the many unused Army trucks, tents and other detritus that are waiting to be removed at America’s biggest base in Afghanistan, the Bagram Air Field in the Parwan province.