Reviewing the Expenses and Responsibilities of leadership (Case Study: Donald Trump’s Critical Approach to NATO)

While some international relations scholars agree and some other disagree with the idea of a decline or weakening in US leadership since the early 1970s (specially affected by the collapse of the Bretton Woods International System), one of the main criteria to examin the notion of a decline in US leadership role is unilateralism in American foreign policy in defining Washington's relations with international institutions, as well as its allies. Meanwhile, Donald Trump's specific approach to post-World War II regimes and international institutions/regimes indicates a marked intensification of the US reconsideration of accepting continued international responsibilities as a world power and global leader. In this regard, Trump's cost/benefit approach (2016-2020) to USA  relations with some international and regional organizations, such as NATO (as the main and most extensive and effective international security regime in the West for the past 70 years)  is considered as the apparent and obvious preference of US national interests over the supportive role of this organization and a kind of breaking tradition of his government's defining US security  relations  and its national interest on both sides of the Atlantic. The current study aims to find both the roots and causes of Trump's critical approach to the security of NATO's European allies and the way this approach could be seen as a sign of declining or weakening US world leadership. Trump's refusal to provide low-cost security for NATO allies was considered as one of the main criteria for the decline of the US leadership role.