Since the 1990s, scholars have expanded the definition of security beyond military force, a process often called "widening" (new sectors) and "deepening" (new levels).
: Analysis often relied on realist theories, viewing international politics as a struggle for power in an anarchic system. 2. Widening and Deepening the Field International and Security Studies Internationa...
: Research now includes economic stability, energy security, and environmental threats like climate change. Since the 1990s, scholars have expanded the definition
Historically, the field was dominated by during the Cold War. Since the 1990s
: Core topics included nuclear deterrence, bipolarity, and conventional military threats.