Which of the following choices best describes 'collective security'?

The concept of 'collective security' is best described as a cooperative response to threats from a common enemy. This principle is rooted in the idea that an attack against one member of a coalition or alliance is considered an attack against all members. Collective security aims to promote international peace and stability by ensuring that states work together to counter aggression and prevent conflict.

Historically, examples such as the United Nations provide frameworks for collective security, where member states agree to respond collectively to acts of aggression. This approach goes beyond merely forming military alliances or participating in economic collaborations, as it emphasizes mutual defense and cooperation in the face of shared threats, fostering a sense of solidarity among nations.

The other options focus on narrow aspects of international relations, rather than the broader collaborative strategy that collective security embodies. For instance, individual self-defense strategies and military alliances do not encapsulate the cooperative spirit inherent in collective security, while economic collaborations are not directly related to the concept of defending against threats.