I'm not sure what you mean by "set up Nations", but if you're referring to our endeavor in Iraq, which involves trying to ensure that the new government that emerges in Iraq is not a threat to us, then the answer to your question is: Yes, of course.
We did the same thing in Germany and Japan. Or was that, too, "setting up Nations" and thus had no relevance to Common Defense in your view?
The current argument hinges on us militarily setting up little Empirical fiefdoms around the globe.
There are better targets that would yield far superior results than anything in the ME. Mexico, Venezuela, and even Canada come to mind.
We beat the hell of of the Axis and had reconstruction plans well under way during WWII in the same amount of time it's taken us to hold our ownin this "police action" in Iraq.
Past due time to piss or get off the pot.