[nradov]

You are misrepresenting what happened with tactical aircraft purchases. Germany, Belgium, and several other countries voluntarily participate in the NATO nuclear sharing program. In order to continue with that they need a nuclear capable aircraft. The US Air Force was already paying to certify the F-35A as a nuclear bomber, so other NATO buyers get that essentially for free. They were free to purchase other aircraft and pay for nuclear certification (like they did previously with the Tornado) but chose not to do so.

https://www.defensenews.com/global/europe/2022/04/13/nato-pl...

The Lockheed-Martin F-16 Viper is still in active production and the Air Force is upgrading theirs with new radars so it's hardly abandoned. It is physically impossible to upgrade a legacy Boeing F/A-18 Hornet to an F/A-18E/F Super Hornet because the airframes are different, but new ones are also still in production. US allies are welcome to purchase either aircraft, but neither one is nuclear capable. Those aircraft are also considered less survivable against Russian air defenses than the F-35, so hardly the same capabilities at all.