So there are apparently various magical communities throughout the world (as evidenced by the various magical schools and sports teams we see). We can assume these communities have their own governments. So my question is, why didn't these governments do anything once Voldemort took over? Wasn't Voldemort a threat to the entire magical world?
My question is somewhat similar to this "Why didn't the other schools help Hogwarts?" but I feel it is different enough.