Article 1, Section 8, Subsection 10 of the Constitution- Congress is authorized to define and punish offenses against the laws of nations. There is nothing in the Constitution limiting the scope of the punishment, either it be a condemnation, sanctions, or a use of force.
Ah, yes...the little known and almost universaly ignored Offenses Clause.
There is very little in the legal literature on the Offenses Clause, although it has recently come into fashion as a possible means to reassert Federal powers that were originally justified under the Commerce Clause during the New Deal and which are now being clawed back. Professor Beth Stevens at Rutgers has suggested that under the Offenses Clause there are literally no powers reserved to the States. But other than this recent appearance, there's not much scholarship on the clause.
There is a decent article
HERE in the Yale Law Review from 2002 on the Offenses Clause.
The thrust of this article is that Professor Stevens interpretation is incorrect. And the article goes on to suggest that the term "Laws of Nations" is derived from
jus cogens norms.
Having read up a bit on the Offenses Clause, mnehrling, I will grant you that it is quite possible to justify Congress's condemnation under this clause.
So in conclusion, Ron Paul is wrong if he claimed that this condemnation was not authorized by the Constitution. And you are right to focus on the Offenses Clause.
Now whether Congress should spend their time on condemnations is another question entirely. And I would argue that they should not. But certainly one could consider it at least some very minor part of "their job".
jas3