Alliances and War V&H, Chapter 1 (Levy)

Introduction Alliance: A formal agreement among a limited number of countries concerning the conditions under which they will or will not employ military force.

COW Alliance Types Defense pact Neutrality/Non-aggression pact Entente

Alliance-War Relationship Alliances make war less likely Balance of Power theory Deterrence They reduce uncertainty

Alliance-War Relationship Alliances make war more likely They generate counter alliances and arms races Audience costs Permanent alliances reduce the number of potential coalitions against the aggressors

Empirical Findings Alliances were associated with peace in the 19th century, but war in the 20th century Alliances make the expansion of war more likely Allies are not reliable during war (Sabrosky); allies are reliable during war (Leeds, Long, and Mitchell)

Jack Levy’s Study He focuses on Great Powers (GP) from 1495-1975 Interstate wars involving at least one GP (119 total, 64 with GP’s on both sides) Question: are alliances necessary and/or sufficient conditions for war?

Number of Alliances Over Time Century 16th 17th 18th 19th 20th Total # of alliances 5 9 15 25 65 119 # of GP 4 5 14 14 40 47 alliances % GP alliances 80% 56% 93% 56% 15% 39%

Necessary Condition Every war (Y) will be preceded by an alliance (X) Some alliances (X) may not lead to war

Necessary Condition No X (Alliance) X No Y (War) 45 55 Y 15

Sufficient Condition Every X (alliance) will be followed by Y (war) Some wars may occur when there is no X (alliance)

Sufficient Condition No X (Alliance) X No Y (War) 35 Y 10 80

Levy’s Conclusions Most alliances were followed by war within 5 years (except the 19th century) Thus alliance is a near sufficient condition for war in most centuries However, most wars were not preceded by alliances Alliances are not necessary conditions for war

Alliance Reliability Do alliance partners come to each other’s aid in war? Allies do what they promise 75% of the time (Leeds, Long, Mitchell)