A significant part of the literature on modern Iranian history has examined foreign colonial influence during the Qajar and Pahlavi periods through a homogenizing lens, overlooking fundamental differences in the nature of colonial domination. This study adopts a qualitative approach grounded in the analytical framework of the Annales School to comparatively examine the nature and mechanisms of Western and Russian influence in Iran within long-term political, cultural, and epistemic structures. The findings indicate that Western colonialism pursued a multilayered and sustainable model of domination in which political and economic mechanisms were deeply intertwined with cultural and epistemic penetration, enabling the reproduction and continuity of influence through internalized norms and institutions. In contrast, Russian influence relied predominantly on political mechanisms and hard power; although effective in certain periods, it lacked cultural and epistemic foundations and therefore failed to achieve long-term continuity. The study concludes that differences in the nature of colonial mechanisms, rather than the degree of external power alone, explain the durability of Western colonial influence and the episodic character of Russian involvement in Iran.