Given that a hypothetical World war 3 would likely involve some electronic warfare, You may find 'current hardware' Stuck on the ground.
An enemy would if it had managed as you suggest to secure airbases that close would have the capacity to render airborne defence problematic.
Plus our armed forces having being reduced would make a ' Battle of Britain' difficult.
Back in the last war they mass produced aircraft .
So maybe you might end up fighting with Spitfires again. Easy to build fast and no Electronic systems. And could probably be retro fitted with modern bullets