As a lifelong smartass, I offer this advice to John McCain: If you make a joke, just let it live or die by the laughter it gets or doesn't get. NEVER immediately explain that, of course, you were just making a joke, in hopes that somebody, somewhere won't take offense. If nobody feels inclined to take offense, it probably wasn't a very funny joke in the first place:
The presumptive Republican presidential nominee was asked about the number of exports going to Iran, specifically the increase in cigarette exports.
McCain looked surprised at that fact and in a line somewhat reminiscent of his "bomb, bomb, bomb, Iran" comment last year said, "Maybe that's a way of killing them." Then he followed it up quickly noting that it was a joke.
Pretty good tactic, actually, unless the U.N. cites us for exporting a weapon of mass destruction. We not only get 'em with the cigarettes, but the secondhand smoke will wipe out the women and children, too.
Just kidding. Only a joke. Lighten up.