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