Aviation set back 20 years when we didnt build the B-70

IMO aviation was set back 20 years when the B-70 was cancelled. Kennedy cancelled it, but it was the fool McNamara that was behind the cancellation. The excuse given was Russian missiles would shoot it down. That was of course hog wash. Look how long the SR-71 flew and was never hit by a Russian missile or one from any other country. Besides that as cruise missiles were developed that the B-70 could have carried, it would still be a viable weapon platform yet today.

In addition with all the thousands of hours experience of supersonic flight, we would probably have fleets of supersonic passenger aircraft.