For nearly two decades, Congress has shaped the U.S. approach to Afghanistan and the ongoing conflict there. Chapter 1 provides a summary of legislative proposals considered in the 115th Congress that relate to U.S. policy in Afghanistan. As reported in chapter 2, the United States, partner countries, and the Afghan government are attempting to reverse recent gains made by the resilient Taliban-led insurgency since the December 2014 transition to a smaller international mission consisting primarily of training and advising the Afghanistan National Defense and Security Forces (ANDSF). The Trump Administration is reportedly considering proposals to deploy additional ground forces to Afghanistan and somewhat broaden their mission. These forces would likely be part of the Resolute Support Mission (RSM), the ongoing NATO mission to train and support Afghan security forces as explained in chapter 3. Chapter 4 provides background information for Congress on the levels of Department of Defense (DOD) troop and contractor personnel deployed in support of prior and ongoing military operations in Iraq and Afghanistan. Chapter 5 addresses (1) what has been reported about ANDSF capabilities and capability gaps and (2) the extent to which DOD has information about the ANDSF's ability to operate and maintain U.S.-purchased equipment.