Question

Whats collective security?

Answer 1

Collective security is when basically multiple groups/nations form a coalition together and agree to not to attack each other, and to help defend from one another or from another threat.

Answer 2

Collective Security is the cooperation of several countries in an alliance to strengthen the security of each.

Sited from:  Beer, Francis A., ed. (1970). Alliances: Latent War Communities in the Contemporary World. New York: Holt, Rinehart, Winston.