No, it's not international law that judges them. It is God's law, written into the fabric of the universe, acknowleged in Blackstone, Epictetus, and the Bible. And the point here? It not only judges governments, but the rest of us as well. If you think it doesn't exist, and I shouldn't insist on its existence, you have just contradicted yourself.
Not that governments won't always try to escape responsibility. In this case, the fictitious double-o status not only exists, but is granted to any European Union police officer who wants to do something: set someone afire, blow up the Parliament building, or anything else that occurs to him.
"But be reasonable," I hear you say. "They won't do that. We can trust them, they're policemen."
The truth is quite simple: no one, no individual and no institution can be trusted with this power. That is a truth so basic that only a little understanding of human nature suffices to establish it (or a quick read of the morning paper).
But doesn't international law apply? See below. No fictitious entity can substitute for God.