SUBSTITUTES OR COMPLEMENTS - THE EFFECTS OF ALLIANCES ON MILITARY SPENDING IN MAJOR POWER RIVALRIES

In the short-term, the mechanisms to address security threats are larg ely confined to building up one's military and securing an alliance wi th another state. This paper seeks to assess the extent to which allia nces substitute for or complement military buildups in major power riv alries over the period 1816-1976 and the conditions under which such e ffects occur. Overall, the results when considering behavior on a year basis indicated, at best, a modest complementary effect of alliances on arms spending increases. Nevertheless, such an effect was not appar ent in all analyses and could not be attributed, mitigated, or exacerb ated according to the type of alliance (e.g., defense pact versus ente nte) or the identity of the alliance partner (i.e., major versus minor power). When considering behavior across the rivalry as a whole, the results were clearer. Non-aggression pacts substituted for arms increa ses in the context of high and increasing defense burdens. Defense pac ts had a complementary effect when they were multi-party alliances tha t expanded the commitments of the major power rivals; this largely res ulted from states entering alliances with small powers after 1945, wit h the resulting free-riding by those small states.