The foreign policy of states determines the way they behave in the international arena. Accurate analysis of official foreign policy documents of a country is helpful in that it shows what the international priorities of a country are at specific periods. This article reviews the U.S. National Security Strategy documents published in 2002, 2006, 2010 and 2015 from the perspective of the perception of threats to the U.S. security and perception of the U.S. role in the world. It tries to study the differences and similarities between the Bush and Obama administrations in this regard using a Neoclassical Realist framework. The results show that the Obama administration identified a wider range of threat sources to U.S. national security while providing less detailed solutions to them. Also, as democracy promotion abroad ceased to be a priority in 2015, compared to 2002 and 2006, counterterrorism continues to be at the top of U.S. security agenda. In line with Neoclassical Realism, creation of an international order under U.S. leadership is an important priority mentioned in the NSS of 2015.
