I was in the Pentagon for the second Regan administration and the Bush administration.
But remember that the US did carry out "regime change" attacks on Grenada (Reagan) and Panama (Bush) during the 80s.
There had been the disastrous attempt to rescue American hostages held by Iran in 1979 which had revealed many issues remaining from Vietnam. The generals during that time had been to the Vietnam School of Warfare and were hesitant.
All of the US military casualties of the Iran assault and half of the US military casualties during the Grenada assault were caused by US accidents and friendly fire not even involving the enemy.
Those errors were primarily because the services simply did not work well together. They went into combat with each service knowing only its own piece of the battle and almost no method of communication and coordination between them. The 1980s was a severe decade of real intention by the Pentagon to get serious about joint warfare.
And let me tell you, I was there in the Pentagon and afterward in one of the new fully joint units (all services within a single unit, cheek and jowl), and the transition was not comfortable or pretty. We literally had shouting matches in the halls, and I was in a couple of them. We didn't have fistfights were I was, but we were intel nerds; there probably were actual fist fights in the joint combat units.
The successful regime change attack on Panama in 1989 began to show some fruit from the effort, but that was a relatively benign operation, in that the US already had a quite heavy military presence in the Canal Zone and the Panamanians were fairly receptive to American presence (they did and still do use the American dollar as their national currency).