As far as I can tell, they're serious. And personally, I find this very disturbing - the attitude of people who very obviously have never been anywhere close to an actual war. Or if they have, and still have this attitude, then this is even more fscked-up than I thought.
Incidentally, they don't seem to be advocating any particular war. Until fairly recently, their site was advocating war with Iraq; now they're advocating war with North Korea, and on their site are hints that they're interested in Syria and Iran soon afterwards. Now, while I may agree with some (most certainly not all!) of their individual statements, the idea of forming a group for the simple purpose of advocating bloodshed in general seems somewhere between lunatic and demoniac.
Perhaps I'm reacting too much to an (amazingly) ill-conceived name; but these people seem like the exact sort of people I would like to keep the hell away from.
