What if the EU and UN declare Bush and Cheney to be international criminals?

Bush, Cheney and their administration probably violated a number of international laws in their outsourced torture operation. Now the investigations are underway.

Spain Looks Into C.I.A.'s Handling of Detainees - New York Times:

...Last week, related investigations were started by the European Union and the Council of Europe to look into reports of secret C.I.A. jails for terrorism suspects in Eastern Europe.

An inquiry seems likely by the United Nations' special rapporteur on torture, Manfred Nowak. Last week he said that if reports of the C.I.A.'s activities proved correct, then the agency was engaged in a 'systematic practice of enforced disappearance.'...

Wouldn't it be "funny" if Bush and Cheney were found to be war criminals, and could not travel to Europe for fear of arrest?

Unlikely of course. They're merely doing what most tyrants do, and the UN is full of tyrants. Most European nations have similar episodes of shame in their recent history. Still, it's good to know at least one investigation is proceeding.