Has a democratic nation invaded another country in the last 100 years?

Well, it still doesn’t meet the OP:

  1. The electorate did not elect him “Fuhrer.” He became absolute dictator by virtue of the Enabling Act and the de facto abandonment of the Weimar constitution.

  2. Germany first invaded another country in 1938, or 1939 if you don’t count Austria and Czechoslovakia. By 1939, Germany was obviously no longer a democracy in any sense of the word.

As to the Serbian war: I think genocide precludes democracy, if only because you’re killing off a portion of the potential voting populace.

And I don’t know how many people would consider the US a democracy prior to the repeal of poll taxes, so that limits our participation.

War Between Democracies – I’m amazed nobody has linked to this yet. It’s an intelligent, exhaustive study of the topic.