Yes, I do agree with you except that I don't think many, indeed most, of those pushing the ET/UFO angle necessarily believed it at all (and I include those at the very highest decision-making levels) - they just went along with it because it suited their needs perfectly! And there was essentially no risk of being caught in a lie! They weren't lying - the reports *could* have been aliens! There was essentially no technology that existed that could prove it either way at the time, and if such technology came to exist later (as it has in some respects, like the airborne radar and visual systems that 'brought down' the Mexican Air Force, so to speak..), then they could simply say - "well they've gone away now - at the time we were working with the best information we had.." and carry on regardless.
I think the UFO=alienz line was pretty much the perfect conspiracy for the 50's thru 70's - it couldn't be disproved (or proven!) then, and as a fleeting airborne phenomena its existence was quite commonplace (of course there are lots of unidentified lights in the skies..) but being fleeting meant it was not available for later re-examination, ie we can't retrospectively use higher resolution photography, better radar equipment and so on. So it was - and remains - undisputable (in the exact dictionary sense).
It could not have been better for the warmongers.. and everyone else who jumped aboard the bandwagon.
I definately think it would be a good thread if you find the time. I have looked at a detailed response but feel it should be on its own thread as there could well be a lot of going back and forth.
I have bolded a part fo your post which is really what needs to be established.
You say you dont think many believed, I guess this is a starting point. I am not convinced that it is all just 'belief' anyway, although I guess a counter to this could well be if that many people 'knew' then the secret would be hard to keep, and if only a few knew then this kind of supports your theory that the rest had other agends and didnt really believe/know but pushed it for other gain as you highlighted in previous post.