I served under Reagan and was reviewing offers for mercenary work during his administration, and I never saw him as an isolationist. It seemed to me that Reagan was everywhere in the world, and he sure was increasing our reach and material in Europe, as he was increasing our global Navy.
You’re generally right but he was smart enough to realize that we had to get out of the Lebannon quagmire (much to the anger of neocon types in the 1980s).
I think you’re quite right that Reagan was not an isolationist.
Reagan’s genius was never having to bring our military might to bear. Our enemies understood that we had the capability to annihilate them, and believed Reagan might just be crazy enough to pull the trigger. Reagan leveraged that threat of annihilation to win the peace.
Huge divergence from the current wave of never-ending limited engagement conflicts.