List of wars between democracies

This is an incomplete list of those conflicts referred to as wars between democracies; many of the references are to the opponents and supporters of the democratic peace theory or liberal peace, which asserts that democracies never or rarely go to war with each other. Definitions of democracy and war vary; two supporters of the theory hold, on different grounds, that there are no exceptions whatever; others hold that it is a strong correlation, and therefore find marginal exceptions to be unsurprising, and in some cases illuminating.

Few students of the democratic peace discuss wars prior to the nineteenth century; democracies were extremely sparse - and whether Athens or Florence is comparable to modern democracies is debateable. Data sets on wars do not always extend back any further; data on much earlier wars - including such questions as the number of troops on each side - are difficult to obtain.

Wars involving the Greek democracies
The Peloponnesian war included a great many conflicts among Greek city-states. The principal war was between Athens (and her allies), most of them democracies, on one side, and Sparta, (and her allies), most of them oligarchies - although most of them held elections among a citizen body. But the war lasted for twenty-seven years, with a brief armistice, and a great many side-conflicts occurred; and states changed from democracy to oligarchy and back again. Most notable of these was the Sicilian Expedition, 415 BC-413 BC, in which Athens went to war with Syracuse. Bruce Russett finds 13 conflicts between "clear" democratic pairs (most of these being Athens and allies in the Sicilian Expedition) and 25 involving "other" democratic pairs.

Athens, like other Greek democracies, was a direct democracy in which decisions on war and peace were taken by an Assembly of the people. Their chief advisors were ten (elected) generals, and orators who held no office, and were under "more direct and immediate control" by their constituents than modern statesmen. Athenian citizens had properly formalized rights, including political, legal, property rights and freedom of speech. Athens, like most Greek democracies, elected the officials in charge of war and foreign policy.

Russett adds that the norms of democracy - and of peace between democratic states - were still evolving; he sees the democratic peace as emerging through time. Athenian domestic politics (the best documented of any Greek state) was not itself peaceable; an unwelcome legislative proposal or an unsuccessful battle could result in a death sentence for the proposer or the general. James Lee Ray also lays stress on the differences between Greek democracy and modern democracies: many Greek democracies had a large non-citizen population, and all of them had slaves - and direct democracy may have different social effects than elections.

Wars involving the Roman Republic
In particular, the Punic Wars, 264 BC-146 BC, with over 1000 deaths in battle. The leaders in both Rome and Carthage were elected. However, both states are usually considered oligarchies. The Roman Republic had large numbers of non-voting slaves, former slaves, Italian allies, and foreigners. Roman citizens had different political rights based on heredity and wealth. The Roman Senate had considerable power and was dominated by noble families.

Eighteenth Century

 * The American Revolution, including the Fourth Anglo-Dutch War of 1780-1784.
 * Pennamite-Yankee War of 1784: Pennsylvania against Connecticut and Vermont.

Nineteenth Century
Like all instances in this article, these depend on how restrictive a definition of democracy is used; some also depend on the definition of war.
 * War of 1812
 * Belgian Revolution against the Netherlands of 1830-8
 * Sonderbund War
 * War of 1849 between the Roman Republic and the Second French Republic
 * War of 1859 between Peru and Ecuador.
 * American Civil War
 * Spanish-American War
 * First and Second Boer Wars.
 * Second Philippine War.

Twentieth Century

 * First World War. All of the Central Powers had elected parliaments; the Reichstag had been elected by universal suffrage, and voted on whether a credit essential to the German conduct of the war should be granted. Whether this is democratic control over the foreign policy of the Kaiser is "a difficult case."
 * Polish-Lithuanian War: Fought in 1920, with about 1000 estimated battle deaths. In both states, elections had been held with universal suffrage. In the polity scale, Poland received a +8 rating in combined democracy/autocracy in 1920, while Lithuania received a +7 in democracy and a +4 in combined democracy/autocracy. The conflict is by both Polish and Lithuanian historians seen as a part of the wars of independence from the Soviet Union (see the article on the Polish-Lithuanian War).
 * Continuation War: A formal state of war between Great Britain and Finland resulting from the Finnish invasion of the Soviet Union in 1941; unlike the formal war between Australia or Canada and Finland, there was actual, if limited, conflict between the two parties.
 * Israeli War of Independence: as against Lebanon.
 * Six-Day War: The Lebanese air force intervened against Israel, both then being democratic states; the same policy set classifies Lebanon as an anocracy, its neologism for imperfect or disputable democracies. although it was called at the time "the only Arab democracy." On the other hand, R. J. Rummel claims, in discussing the Israeli attack on the USS Liberty, that Israel was "only partially free" in 1967 - because of the economic policies of the Israeli Labour Party.
 * Paquisha War: War fought in 1981 between Ecuador and Peru. The leaders of both countries had been democratically elected. Ecuador receives a rating of +9 in the polity scale of combined democracy/autocracy, while Peru receives a +7, meaning that both countries are classified as democratic, and Ecuador even as "very democratic". However, the "war" involved only as high as two hundred deaths in battle. Furthermore, the Peruvian democracy was less than one year old and the Ecuadorian less than 3 years. In addition, both nations lacked democratic control over their militaries. p. 70, 316.

Definition dependence
Almost all of these depend on the definition of "democracy" (and of "war") employed. As James Lee Ray points out, with a sufficiently restrictive definition of democracy, there will be no wars between democracies: define democracy as true universal suffrage, the right of all - including children - to vote, and there have been no democracies, and so no wars between them.

On the other hand, Ray lists the following as having been called wars between democracies, with broader definitions of democracy: The American Revolution including the Fourth Anglo-Dutch War, the French Revolutionary Wars, the War of 1812, the Belgian Revolution, the Sonderbund War, the war of 1849 between the Roman Republic and the Second French Republic, the American Civil War, the Spanish American War, the Second Phillippine War, the Second Boer War, World War I, World War II (as a whole, and also the Continuation War by itself), the Israeli War of Independence, the Indo-Pakistani War of 1947-1948, the Six-Day War, the Yugoslav Civil War, and the Armenia-Azerbaijan War.