Vietnam was a crucible where a lot of entrenched thinking had to be burned away, unfortunately those lessons were taught in the context of that awful conflict.
Trivia: the Soviets eventually recovered an intact downed Sabre and shipped it to Russia for evaluation. They copied from it, including the Sabre's gun-sight that later fitted out the MIGs in Vietnam.
Did the F86 ever serve in the Vietnam war?
The F100 was the first jet that could fly supersonic in level flight. It was known as the widowmaker, as it was basically a subsonic aircraft that could go supersonic, with pre-supersonic cockpit and controls. The workload on the pilots was intense, and many pilots died in flight school.
Since it was basically obsolete, it was used as ground attack aircraft, with fighter support provided by F105s.
Source: family member flew F100s in Vietnam
No. The National Guard had them through the 1960s but jet fighter technology was moving so fast at the time that they were not in front line service by the time the US had any involvement in Vietnam.
That in itself is a crucial piece of historical context. The MiGs of the day were better than contemporary American fighters such as the F-86. They operated at altitudes the Americans couldn’t reach and shot downwards. One reason America was in Vietnam in the first place was a genuine fear that the Soviet system was actually better! It was the Sidewinder missile that really turned things around.