Real and perceived threats to security are among the major concerns of both governments and citizens all over the world. Nowadays, the potentially hostile nuclear pretensions of some countries have been at the center of the international stage. The fear of a nuclear threat and conflict raises the highest concerns usually expressed by the media and elected political officials. Historical examples of the bombing of Hiroshima and Nagasaki are sufficient to convince anyone that, in a full scale conflict, we can assist to the destruction of the entire human civilization. Lately, many have argued for international cooperation and multilateral action on the limitation of nuclear armament as a precondition for international peace and security.

The main aim of this paper is to understand what characterizes the current U.S. nuclear strategy, comparing Bush and Obama policies. The core elements under discussion here are related to the perception of the appropriate role of nuclear weapons, i.e. arms control, disarmament and nonproliferation initiatives. Furthermore, this paper comes at a time when threats have changed and the world has moved closer to a proliferation tipping point. Armed conflicts, ethnic and religious strife, extremism, terrorism and the proliferation of WMD constitute significant challenges to security and development worldwide and are a regular topic on news. In this sense, the paper will be divided in three sections: (1) presentation of main characteristics of the U.S. nuclear strategy; (2) to examine the contemporary debate about nuclear weapons; (3) analysis of the differences between Bush and Obama nuclear policies and their outcomes.