Adapting Uncertainty: An International Relations Perspective on Modern Defence Strategy

Abstract

International Relations (IR) and defence strategy have become increasingly intertwined as states confront a complex security environment shaped by geopolitical competition, technological disruption, and emerging non-traditional threats. This study examines how states formulate and adapt defence strategies within the evolving international system, with particular attention to the role of alliances, deterrence, and technological innovation. Drawing on key theories of IR—including realism, liberal institutionalism, and constructivism—the research explores how shifts in global power dynamics influence military planning, capability development, and strategic posture. It further assesses the impact of cyber warfare, artificial intelligence, and autonomous systems in reshaping traditional concepts of deterrence and national security.

Through a comparative analysis of selected case studies, the paper highlights the strategic behaviours of major powers and regional actors, demonstrating how defence strategies are used to manage threats, strengthen alliances, and achieve geopolitical objectives. The findings reveal that while military power remains central, contemporary defence strategy increasingly requires integration across diplomatic, economic, technological, and information domains. The study concludes that effective defence strategy in the 21st century demands adaptability, multi-domain coordination, and a deep understanding of international political dynamics. This research contributes to broader debates in IR by offering insights into how states can enhance national security while navigating an uncertain and rapidly transforming global security environment.