(Why, yes, I am experiencing a burst of energy after weeks of being sick, thank you for asking.)
So Bruce Franklin's M.I.A: Mythmaking in America, which is a very good book, has a fascinating but sadly brief mention that in 1979-1980, Chinese intelligence agents in Southeast Asia deliberately spread stories of live US POWs in order to damage US-Vietnamese relations. Unfortunately the only reference is a Vietnamese govenment pamphlet. So, a) anyone heard any mention of this elsewhere, and b) does it sound credible? It does to me, save that I wonder how the Chinese, hardly the most culturally astute nation at the time, would have picked up on the American POW obsession.