Mw. Simon et E. Gartzke, POLITICAL-SYSTEM SIMILARITY AND THE CHOICE OF ALLIES - DO DEMOCRACIESFLOCK TOGETHER, OR DO OPPOSITES ATTRACT, The Journal of conflict resolution, 40(4), 1996, pp. 617-635
Does the nature of a nation's political institutions influence the typ
es of countries with which it allies? Some previous research has sugge
sted that democracies tend to ally with other democracies. This study
reexamines alliance patterns by assessing the broader linkage between
regime type and alliance partnership. The authors present a refinement
of previous research designs, using new data from Polity III and the
updated correlates of war (COW) alliance data sets to analyze all alli
ances from 1815 to 1992. The bipolar alliance structures of the cold w
ar (NATO and the Warsaw Pact) appear to be aberrations in their strong
ideological content In general, there is very little correlation betw
een alliance dyads and regime type. Surprisingly, democracies are less
likely to ally with one another than highly autocratic regimes. Regim
es of most types seem to prefer to ally with partners of dissimilar ty
pe. The authors conclude that this is due to so-called gains from trad
e within alliance dyads.