The F-35 was commissioned by the US 20 years ago, but its development has been costly and slow

As two gleaming F-35A Lightning II warplanes touched down at Bulgaria’s Graf Ignatievo airbase in April, dignitaries and pilots drummed home the official message: that the fifth generation jets were the most lethal, efficient and well-connected ever built.

After the Bulgarian president, himself a MiG-29 pilot, welcomed the aircraft on its first European training deployment, US Air Force commanders spoke of how the F-35 “brought to bear truly game-changing capability”.

“The F-35 pulls in all the information that the sensors detect and passes that to me, thereby increasing the lethality of all the other fighters airborne,” Major Luke Harris, an F-35 pilot from the US air force 34th Fighter Squadron, said. “Any other aircraft we’re flying with are made better by the F-35.”

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