Operation Enduring Freedom, the worldwide combat mission launched shortly after the terrorist attacks of Sept. 11, 2001, that eventually became synonymous with the 13-year war in Afghanistan, officially ended Sunday.
Up to 10,800 U.S. troops will remain in Afghanistan in 2015 and the mission will be renamed "Operation Freedom's Sentinel." Military officials say that will be a narrowly defined two-prong mission: advising the Afghan army and continuing to mount counterterrorism operations against the Taliban and other insurgents who may pose a threat to the U.S. or Afghan governments.
Obama's current strategy calls for reducing the U.S. force level to about 5,000 in 2016 until a complete end of the military mission there before he leaves the White House in 2017.
The early years of OEF encompassed missions around the world. Many U.S. troops supporting the invasion of Iraq in 2003 were technically deployed under OEF orders. And it also included counterterrorism operations in Southeast Asia, North Africa and elsewhere.
For years, the war operations in Afghanistan were comparatively small. U.S. troop levels there remained below 30,000 until 2008, when the Taliban insurgency began gaining ground and threatening the American-backed government. U.S. troop levels peaked at around 100,000 in 2010.
Pessimism about the military mission in Afghanistan has grown during the past several years.
According to a Military Times reader survey, the percentage of active-duty service members who say the U.S. ultimately is "very likely" or "somewhat likely" to succeed in Afghanistan has dropped from 76 percent in 2007 to 23 percent in 2014.
A similar trend is reported among civilians. While the mission was overwhelmingly popular when it began in October 2001, a Gallup Poll in 2014 showed that about half of Americans believe sending troops to Afghanistan was a mistake.
Andrew Tilghman is the executive editor for Military Times. He is a former Military Times Pentagon reporter and served as a Middle East correspondent for the Stars and Stripes. Before covering the military, he worked as a reporter for the Houston Chronicle in Texas, the Albany Times Union in New York and The Associated Press in Milwaukee.