War between democracies

[buritobr]

Now, talking about wars in which both sides have democratic regimes.
There is a theory which says that democracies don't go to war against each other. It is hard to say if this theory is true or false because it is hard to define what is democracy and what is a war.

Some examples
Peloponnesian War: a war between democratic Athens and undemocratic Sparta. But Sparta had an elected council, so some would argue that Sparta was a semi-democracy
Anglo American War (1812-1815): war between two countries who had liberal regimes. However, it is not easy to say that the liberal US and UK regimes of that time were democratic because neither of the two countries had universal suffrage
American Civil War: Both USA and CSA had elected governments, but no universal suffrage
First World War: The Second Reich had a parliament elected by universal suffrage. However, the vote of the rich had more value than the vote of the poor. Kaiser Wilhelm had too much power. Sometimes, anti-socialist laws limited political activity
French occupation of the Ruhr (1923): There is no doubt that French Third Republic and Weimar Republic were democracies. But it was only an invasion, not a clash between two armies
Second World War: Finland was the only democracy in the Axis. There were some battles between Finnish and British forces
Equator vs. Peru wars: in 1981, OK. In 1995, as I mentioned in the other thread, Fujimori was not very democratic, although he was elected
Yugoslavia Wars in the 1990s: Slobodan Milosevic was an elected president. But not in fair elections. His government was oppresive
Israel vs Palestine: both have elected governments

Problem of the theory which predicts that democracies are safer: in 2003, the war between USA and Iraq was a war between a democracy and an autocracy. But the side who started the war was the democracy.

Some could argue that there is no causation between being a democracy and not going to war. This could be only a coincidence, considering that interstate wars became old fashioned after 1945, and there were few democracies until 1945. Interstate wars became even more old fashioned after 1990 when the number of dictactorships decreased even further.
On the other hand, it is possible to argue that interstate wars decreased as a consequence of the spread of the democracies.

[Oak Hills]

I don't think examples of democracies fighting each other really refutes the theory.  I still think it's reasonable to conclude democracies are less likely to fight against each other, but not that they never do.

[The Mikado]

Israel vs Lebanon 2006 is a pretty clear-cut refutation.

[politicus]

@buritobr: Democracies in this context should be understood as countries with universal adult suffrage, and an established democratic political culture (so excluding very new and fragile demcracies where large parts of the population are anti-democratic), which makes some of the examples you mention irrelevant.

(the theory is not that countries with elected parliaments do not go to war with each other, but that fully developed democracies do not)

Lebanon is a dubious example because it was (and is) a state where the central government does not control all of its territory and is unable to establish an efficient monopoly of violence. The Israelis attacked Hezbollah, which is a non-democratic entity (based on territory legally belonging to a democracy). It is therefore also - more accurately - called the 2006 Israel–Hezbollah War.

[buritobr]

The same is valid for Colombia invading the territory of Equator in 2008. It was not a war against Equator. It was a war against FARC. But there were some FARC guerrilas hiding in Equator.