This publication is the second in a series of lessons learned reports which examine how the U.S. government and Departments of Defense, State, and Justice carried out reconstruction programs in Afghanistan. In particular, the report analyzes security sector assistance (SSA) programs to create, train and advise the Afghan National Defense and Security Forces (ANDSF) between 2002 and 2016. This publication concludes that the effort to train the ANDSF needs to continue, and provides recommendations for the SSA programs to be improved, based on lessons learned from careful analysis of real reconstruction situations in Afghanistan. The publication states that the United States was never prepared to help create Afghan police and military forces capable of protecting that country from internal and external threats. It is the hope of the Special Inspector General for Afghanistan Reconstruction (SIGAR), John F. Sopko, that this publication, and other SIGAR reports will create a body of work that can help provide reasonable solutions to help United States agencies and military forces improve reconstruction efforts in Afghanistan. Related items: Counterterrorism publications can be found here: https://bookstore.gpo.gov/catalog/counterterrorism Counterinsurgency publications can be found here: https://bookstore.gpo.gov/catalog/counterinsurgency Warfare & Military Strategy publications can be found here: https://bookstore.gpo.gov/catalog/warfare-military-strategy Afghanistan War publications can be found here: https://bookstore.gpo.gov/catalog/afghanistan-war