Before the 9/11 terrorist attacks, Afghanistan was neglected and left behind by the international community. Following this event, it became clear that Afghanistan posed a menace to international security. The focus of the international community soon shifted towards Afghanistan. The response to the September 11th events was an intervention by the USA that has overthrown the Taliban regime. The overthrow of the Taliban regime has laid the foundations for the implementation of the future security sector reform in order to achive security and stability in Afghanistan. Security sector reform includes five pillars: the reform of the Afghan National Army, the reform of the Afghan National Police, the reform of the judiciary, the fight against narcotics, and the disarmament, demobilization, and reintegration project. All pillars of security sector reform are extremely important for its success. The goal of this research is to determine whether the reform of the security sector, from its establishment until 2020, created institutions that enable stability and security in Afghanistan. Not only is the security and stability necessary for the future development and progress of Afghanistan, it also reduces potential threats to regional and international security.