Bush played isolationist in the 2000 election, but the people he lined up in his actual gov't once he took power clearly were not. So it was always going to turn out the way it did, with him continuing the little quests his father and Reagan were on.

It's just the same internal power play within the GOP for decades. Explicitly imperialist adventurism, or a sad attempt isolationist foreign policy that never actually happens. See the way they're incoherent on Ukraine, now.