Approved for public release; distribution is unlimited / This thesis strives to shed light on the genuine significance of the current transformation of the U.S. foreign and strategic policy. In essence, this thesis concludes that the Bush doctrine of preemption is inconsistent with the American strategic culture and view of the use of force displayed throughout the American foreign policy ever since the Truman administration. Although not a revolution per se in the American goals, the new foreign policy represents a radical change in the manner to pursue them. While promoting a unilateralist foreign policy and revived "warfighting" strategies, the current administration takes old rationales a step further. By elevating preemption from the tactical to strategic level, the doctrine transforms a last resort policy option into a primary offensive strategy with destabilizing consequences for international relations. The analysis concludes that the increased authority of the hard-line approach in the American foreign and security policy is circumstantial, and the likelihood of its endurance is unrealistic. The international system comprises built-in constraints that raise the cost of isolationist and unilateralist impulses to unbearable levels in the long term. These constraints are the end result of the American national values' projection at international level. / Civilian, Romania Ministry of Foreign Affairs