This paper examines the instrumental role of Dashnaktsutyun, also known as the Armenian Revolutionary Federation, in the geopolitical strategies of the British Empire during the early 20th century. Initially emerging as a nationalist movement within the Ottoman Empire, Dashnaktsutyun was co-opted by external powers, particularly Britain, to serve broader imperial interests in the Eurasian region. The study delves into the organization’s activities in the Ottoman, Russian, and Iranian territories, highlighting how its operations, under the guise of Armenian nationalism, were significantly influenced by British geopolitical objectives. The paper also explores the complex interplay between nationalist movements and international power politics, particularly in the context of the Great Game between the British and Russian Empires. A critical analysis of Dashnaktsutyun’s role during key historical events, such as the Soviet invasion of Armenia in 1920, reveals a prioritization of foreign directives over national resistance, impacting the trajectory of Armenian history and reflecting the broader dynamics of early 20th-century imperialism. This study serves as a cautionary tale of how nationalist movements can be redirected by external influences, often at the expense of their foundational principles and the welfare of their people. Keywords: Dashnaktsutyun, Armenian Revolutionary Federation, British Geopolitical Strategy, Armenian Nationalism, Imperialism, Soviet Invasion of Armenia, Great Game, Pan-Islamism, Pan-Turanism