This is always a judgement call, and historically, the US has drawn the line a lot further over on the side of free speech than Europe. I'm pretty sure that if Pastor Jones had been in England he'd have been arrested just for proposing his trial and burning; he'd certainly be in jail now. Likewise the Wesborough Baptist Gay-haters. It is arguable that our political debate is that much less free as a result: but with all due respect, the US's wider limits for speech don't seem to have produced a markedly higher level of wisdom in the debate.
The real problem internationally is the same kind of cultural incomprehension that bedevils so much international debate. The countries that feel attacked by this have such radically different traditions of politics that they honestly do not believe that the President of the world's most heavily armed nation can only show his disapproval of this by wringing his hands in distress. One can understand why. If something similar (mutatis mutandis) happened in a Middle Eastern state, and the perpetrator went unharmed, we would take it as proved that his actions were at least approved, if not actually sponsored by the government.