With the emergence of new threats after the Cold War and the enlargement process of the European Union (EU), the Mediterranean Sea has become more important for Transatlantic security. The European Union has taken initiatives to cooperate in the Mediterranean region since 1970 onwards, but these initiatives have been shaped within the framework of stable neighbors. However, as a result of the developments in the Middle East and North Africa after the end of the Soviet threat to the Western security, NATO as well as the EU, looked for increasing cooperation between the south and north; in order to contribute to international security. However, unlike the EU, NATO has been seeking a strategic partnership to prevent conflicts in the Mediterranean. Unstable states, rising radical Islam and the increase of weapons of mass destruction let NATO to the Mediterranean. As a result of the elimination of mutual distrust, joint security can be extended to the Mediterranean Sea. This study examines the development of EU and NATO Mediterranean policies and tries to analyze similar and differentiated points. Within this framework, in the light of the information obtained, it is seen that NATO, which is referred to as a hard power, and the EU, which emerges as a normative power, remained inadequate and ineffective at the political partnership in the Mediterranean.