The third part of the book analyzes the impact of President Donald Trump’s America First policy on international relations, rooted in his “Make America Great Again” (MAGA) doctrine. ​ It explores Trump’s nationalist, conservative beliefs, business background, anti-establishment agenda, and populist appeal amid US socio-political polarization and economic challenges. ​ The study argues that Trump’s proclivity for solipsism and narcissism, coupled with his mercantilist and transactional mindset, shaped his erratic foreign policy decisions. ​ The introductory chapter also compares Trump’s foreign policy approach with those of other twenty-first-century US presidents, while contrasting his preference for bilateralism with Bush’s predilection for unilateralism and Obama’s and Biden’s preference for multilateralism. ​ It also sheds light on the differences in Trump’s foreign and security policies during his first and second presidential terms. ​