Cable: "when I read that Gagarin was not the first man in space ... and some suggest that both Us and soviets lied ... so I'm entitled to be suspicious. "

Your suspicions are superficially justified, since these stories have been circulating for more than forty years. However, you are also intellectually obligated to see if these stories can be verified or debunked by serious historical investigation, and they have been the latter for about thirty years. This is a good example of the 'level of evidence' often presented by HB's, that is, "I heard a rumor" is given just as much credence as "verifiable evidence and first-hand testimony indicates..."

see
http://www.jamesoberg.com/usd10.html