Respuesta :

PhyCS
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.
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.