Proceedings of 7th Global Business and Social Science Research Conference 13 - 14 June, 2013, Radisson Blu Hotel, Beijing, China, ISBN: 978-1-922069-26-9 Is it About Time of Rethinking American Extended Deterrence: The Examples of Turkey and South Korea Nursin Atesoglu Guney Due to the probability of having new nuclear hopefuls- like Iran and North Korea- in 21st century, the deterrence theory that used to cope with security threats in the past now seem to be in jeopardy. Since, the World order power configuration has radically changed in the post-Cold War to include both state and non-state actors as well as the America’s preponderant position towards the other great powers; the main dynamics of deterrence theory has also altered. Today, the existence of the new security threats necessitates the actors of international community dealing with them via new and evolving tools of the complex deterrence. That is why, the new issues of WMD proliferation in worldwide sense has become quite debatable. The question is came about, whether the countries like Turkey and South Korea can meet their current and future security concerns via the present US extended deterrence means or not. In this regard, each of the individual cases of Turkey and South Korea will tried to be assessed in line with both the new realities of the radically changed security environment and along the present parameters of the American extended security guarantee. KEY WORDS: South Korea, External Deterrence, Turkey, Regional Security ________________________________________________________________ Prof.Dr. Nursin Atesoglu GUNEY, Yildiz Technical University, Istanbul, Turkey.