This paper aims to analyse the reasons Switzerland decided to join the Partnership for Peace (PfP) in 1996. Switzerland is a country in Europe that embraces the principles of neutrality. This principle of neutrality arise due to xenophobia factor that lead Switzerland to shut away from any interaction with the outside world, such as international cooperation and just focused on maintaining sovereignty. Post-cold war, new issues such as terrorism, weapons of mass destruction and environmental damage appear as a cross-border threats which require Switzerland to have international cooperation. Patnership for Peace (PfP) is one of the cooperation that Switzerland chooses to confront these issues. PfP is a program that made by NATO in 1994 with the aim to promote cooperation and stability of European countries, as well as to continue to improve interoperability.