Final answer:
From 2010 to 2015, the U.S. Marines were involved in counterinsurgency operations, training Afghan forces, and providing security in Afghanistan, particularly in Helmand Province.
Step-by-step explanation:
Between 2010 and 2015, during Operation Enduring Freedom, the United States Marine Corps played a vital role in combat operations in Afghanistan. According to Figure 32.4, Marines were actively engaged in fighting against Taliban forces, notably in Helmand Province, which was a stronghold for the Taliban.
The Marines' role included conducting counterinsurgency operations, training the Afghan National Security Forces, and providing security to enable reconstruction and stabilization efforts in the region.
Moreover, as noted in the May 2014 announcement by President Obama, the combat operations of U.S. forces had largely ended by this time. However, Marines were among the residual forces that remained to continue training the Afghan army, with a focus on transitioning to an advisory role to support the Afghan government and its forces.
The decline of the "One weekend a month, two weeks a year" military service slogan reflects the increased commitment and extended tours of duty that Reservists, including the Marines, faced during operations in Iraq and Afghanistan.
The Marine Corps, along with other U.S. military branches, continued to adapt to changing conditions on the ground, supporting the United States' broader goals in the region and contributing to the efforts to establish a stable and democratic Afghan government.