From the Document: "Afghanistan has been a central U.S. foreign policy concern since 2001, when the United States, in response to the terrorist attacks of September 11, 2001, led a military campaign against Al Qaeda and the Taliban government that harbored and supported it. In the intervening 17 years, the United States has suffered around 2,400 fatalities in Afghanistan (including seven in 2019 to date) and Congress has appropriated approximately $133 billion for reconstruction there. In that time, an elected Afghan government has replaced the Taliban, and nearly every measure of human development has improved, although future prospects of those measures remain mixed. The fundamental objective of U.S. efforts in Afghanistan is 'preventing any further attacks on the United States by terrorists enjoying safe haven or support in Afghanistan.'"
CRS Report for Congress, R45122
Congressional Research Service: https://crsreports.congress.gov/