306 CHAPTER EigHT ■ War and Strife
by united action: all (or many) states will unite against the aggressor. Potential aggres-
sors will know this fact ahead of time, and thus, will choose not to act.
Collective security makes several fundamental assumptions.^33 One assumption is
that the collective benefit of peace outweighs the individual benefits of war, even a suc-
cessful war. Another assumption is that aggressors—no matter who they are, friends
or foes— must be stopped. This assumption presumes that other members of the inter-
national community can easily identify the aggressor. Collective security also assumes
moral clarity: the aggressor is morally wrong because all aggressors are morally wrong,
and all those who are right must act in unison to meet the aggression. Fi nally, collec-
tive security assumes that aggressors know that the international community will act
to punish an aggressor.
Of course, this idea is none other than deterrence, but with a twist. If all countries
know that the international community will punish aggression, then would-be aggressors
will be deterred from engaging in aggressive activity. The twist is that in liberal theory,
states are more likely to calculate their interests collectively as shared interests rather
than individually, as in the realist view. Both theoretical perspectives accept alliances
as a fundamental aspect of interstate politics, but liberals put more faith in them than
realists do. Hence, states will be more secure in the belief that would-be aggressors
will be deterred by the prospect of united action by the international community. But
for collective security to work, the threat to take action must be credible, and there
must be cohesion among all the potential enforcers.
Collective security does not always work. In the period between the two world wars,
Japan invaded Manchuria and Italy overran Ethiopia. In neither case did other states
act as if it was in their collective interest to respond. Were Manchuria and Ethiopia
really worth a world war? In these instances, collective security did not work because,
as realists assert, the states capable of acting to halt the vio lence (particularly Britain
and France) could not see sufficient national interest in doing so, especially when the
aSSumptionS of ColleCtive
SeCurity theory■ Wars are caused by aggressive
states.
■ Aggressors must be stopped.
■ Aggressors are easily identified.■ Aggression is always wrong.
■ Aggressors will be deterred from
aggression by the credible threat
of a collective response.in foCuS