Normally, I would agree with you, however, that is why I mentioned the difference (if these are citizens) and who they intend to fight. If they were intending to fight government troops (from here or some other nation) in defense of their communities...yes, that is (in my opinion anyway) what the 2nd Amendment is about. However, if they are training to wreak havoc in the civilian populace...that is completely different. They have a right to assemble, a right to own and train with their arms...([i]IF they are citizens, anyway[i]) but not to murder their neighbors or cause hysteria.
While it is agreed citizens of our various countries have rights, we aren't in the business (or shouldn't be) of guaranteeing citizens of OTHER nations to take them from ours.
Having a right to something doesn't mean it should be GIVEN to someone, only that he or she can strive to attain it. The government isn't handing out too many rifles these days to civilians, after all...
that's mostly why I think there is a difference. Murderers prior to committing their crime, may have a right to own certain arms. They are not however given the right to commit murder. It's a fine line to me, anyway.
John P.