I take your point Carol - I have long said that militant Islamism has replaced Marxism as the worldwide threat. But the difference is that Vietnam is a specific geographical location {the threat that, if victorious there, they would somehow sail the Pacific & overrun the American continent was patently absurd}; while the Islamist movement I refer to can, and does, move about; shifting its training camps from Pakistan to N Nigeria to Yemen [or running all simultaneously]; and the bombers are as likely to come from within, like Richard Reid the 'shoe-bomber' and the 7/7 London Underground terrorists who came from no further away than Yorkshire, as from outside. Vietnamese Marxists did not move to the USA or UK - and certainly were not born in either like some of the recent bombers - but were operative purely within their own territory, where it is indeed at least arguable as to whether USA had any right whatever to pursue the Marxists among them. The same does not apply to our own Bradford-born bombers. If you persist in regarding them as nothing but 'boogey·men' I suspect you might receive quite a nasty surprise before you are very much older,