"A pre-emptive war initiated by Germany is also what happened in the 30's.

That's why any pre-emptive war is illegal, in international law, unless there's a clear case of self-defense."

How many wars has France been any war since '30s, how many were illegal and legal according to how you define illegal?
Was America's war in Vietnam illegal? And what about Afghanistan?

Was the Geman invasion of France "pre-emptive"?
If a country has declared war with another country and that country attacks the country that has declared it's at war with can you apply these pre-emptive principles?
Was it only at the point in which Germany invaded Poland that Germany had started a pre-emptive war? How would you characterize Germany's earlier aggressive behaviour? For instance breaking it's various surrender conditions [from WWI].
Upon Iraq invading Kuwait was this declared illegal by the UN and what would the rest of the world had done if America decided it wasn't interested in using it's miltary power to change this situation? Or I guess the first question is do you consider Iraq's invasion of Kuwait as pre-emptive and illegal.