Michael Walzer delineates the conception of just and unjust wars and states that no war can be just on both sides, though a war can be unjust on both sides. In general, war is unjust for the one at fault and just for the defender against aggression. Walzer indicates how the legalist paradigm of aggression has been used to differentiate between the two, between the just and the unjust war. This paradigm begins with the domestic analogy which holds that aggression is the international equivalent of armed robbery or murder. Walzer points out that international society is and is not like domestic relationships, but to the degree that it is like domestic relationships, the legalist paradigm may suffice to demonstrate who is at fault. International aggression is worse than domestic crime because the threat is so much greater and there is no policeman to act as protector. There are police powers, but they are dispersed through all the members of the society. However, the United states has often acted as world policeman, a role that the U.S. denies is its intention or goal, but one that it is seen as having undertaken on several occasions. Two such occasions can be found in the intervention in the Dominican Republic in 1965 and the invasion of Grenada in 1983. These will be analyzed according to the legalist paradigm to qualify them as just or unjust wars and to test the use of the paradigm.
Walzer makes two assumptions based on the domestic analogy as it pertains to the legalist paradigm in international aggression: 1) there is a presumption in favor of military resistance once aggression has begun, and such resistance is important so that rights can be maintained and future aggressors deterred; and 2) when fighting does break out, there must always be some state against which the law can hold and should be enforced--there must be an aggressor who is responsible. Walzer calls the primary form of the theory of just and unjust wa...