I think a pretty good distinction can be made between a world not subject to a rule of law and a nation that is. There is no enforceable law globally, nor an executive capable of enforcing it. In such a situation, acting as if there are constraints on your nation's behavior will endanger your citizenry through the unconstrained actions of other nations. Consequently, we are left with a situation where we do what we must in global politics. Criminal behavior is a lot different when the subject is the relationships nation-states have with each other.
However, that same situation is not applicable to events within a given nation, where there is an effective executive and a set of laws to govern behavior. Therefore, equating the two situations is not logical.
If you don't believe me, try imposing custom duties on your neighbor.
- trask