This question was inspired by a largely unanswered related question, but it is a bit broader:
Did the international community react or respond, in any way, to Voldemort?
The actions of his regime, each time he rose to power, seemed like they definitely warranted a response. (If a muggle dictator deposed the government of Britain and started purging the populace, there would be quite the reaction.)
We know that there is an international community of Wizards, at least as far-off as France and eastern Europe as seen in Goblet of Fire and Egypt as seen in Prisoner of Azkaban. Now, Voldemort seems to have had some international presence himself (Igor Karkaroff was a Death Eater), but Voldemort seems to be more of a British figure than a world-conqueror. As far as I can tell, there are areas outside of Britain that Voldemort never controlled, nor even attempted to control. And it seems like someone of Voldemort's ambition and ego would be unlikely to just ignore external threats to his reign (and his oh-so-very-precious life).
Additionally, several actions taken by Voldemort and his followers could easily have drawn attention even in the muggle press, (and if the British PM knows about wizards, presumably the American President does, as does any major head of state). Obviously the wizards will be taking steps to maintain their anonymity, but it's tough to control other governments when you're blowing up bridges...
I think it's safe to say no one started a World War II-style alliance to liberate Britain from Voldemort's control. That would definitely have altered the course of the story.
But was there any international response at all?
