You are incorrect. Most laws prohibit actions, by any citizen of any country, in the territory that has that law. Most laws have no effect outside of the state that has them.Originally posted by Atahualpa
The way I understand this is: If you are citizen of some country you have to obey their laws.
So if Arnold has enforced the Death Penalty he violated austrian laws, thus he can be tried here.
Even if this would be in accordance with US laws.
It's the same with e.g. you traveling to the netherlands and smoking weed. Theoretically your government could arrest you at home, if they have evidence that you went to the netherlands and smoked weed there.
Laws that are imposed against any citizen, anywhere, doing certain things (like some countries have passed laws regarding child sex tourism) are a very different matter.
There is also the small matter of violating the sovereignty of other states by enforcing your laws on citizens in their country.
What would you be saying if the Saudis punished Saudi women who travelled to Austria and took off their head coverings, or any Saudi who travelled to Austria and got drunk?