Why no Viet Nam? Because Nixon wins in '60 (he did anyway, but that's another story). With Nixon instead of JFK, no Viet Nam, no Great Society, and Apollo is very likely *very* different. *Perhaps* NASAs directive is changed: instead of getting to the Moon ASAP, the US ends up with a Nova program. Maybe the Russians get to the Moon first, but the US is orbiting million pound payloads by 71 or so. No JFK, perhaps no test ban treaty, so some of those Nova payloads are *Orions.* With a vastly different and much more entrenched space program, the aerospace industry as a whole is kicked into high gear. With that stronger base and a much better economy due to no Great Society moneypits, the US gets SSTs, "battlecruiser" interceptors, high-Mach recon planes.
With a simple change in Presidents in 1960, everything else changes. 1968 almost certainly doesn't have the same raft of political assassinations (and of course there wouldn't be the fairly recent memory of JFK in Dallas). Without those, maybe cities don't burn. Of course, there could be a completely *different* set of assassinations, and even more cities burn. If society is more stable, everybody is richer; VTOL regional/short range jetliners perhaps get off the ground. *Maybe* the OPEC oil embargo doesn't happen and the economy of the 1970s is actually *good,* so SSTs and VTOL jets can be economically successful.
Lots of maybes.
With a simple change in Presidents in 1960, everything else changes. 1968 almost certainly doesn't have the same raft of political assassinations (and of course there wouldn't be the fairly recent memory of JFK in Dallas). Without those, maybe cities don't burn. Of course, there could be a completely *different* set of assassinations, and even more cities burn. If society is more stable, everybody is richer; VTOL regional/short range jetliners perhaps get off the ground. *Maybe* the OPEC oil embargo doesn't happen and the economy of the 1970s is actually *good,* so SSTs and VTOL jets can be economically successful.
Lots of maybes.