This thesis examines the process of decolonization during the Cold War through the comparative case studies of Egypt and Cyprus, focusing on the interplay between colonial decline and nationalist movements, under the scope of US foreign policy and regional interests. It argues that while the post-1945 global order appeared to favor national self-determination, decolonization was profoundly shaped by Cold War dynamics and US strategic interests. By combining the theoretical frameworks of Realism and Post-colonial Theory, the study explores how the United States emerged as both a promoter and a regulator of decolonization by supporting independence rhetorically, while ensuring that newly sovereign states remained aligned with Western interests. In Egypt, American involvement evolved from cautious encouragement of British withdrawal to confrontation with Nasser’s nationalist and non-aligned agenda, illustrating Washington’s attempt to balance anti-colonial legitimacy with geopolitical containment. In Cyprus, the US prioritized NATO stability over the island’s self-determination, favoring compromise arrangements that maintained Western cohesion.