**Which sort of goes hand-in-hand. If you're pro-business, you're less tolerant of anything that gets in the way of that, including foreign activities that may impede business. De-emphasizing business seems to mean less interest in foreign matters.

I will grant you this point, with some modifications.
The GOP has traditionally oscillated between having an interventionalist viewpoint to an isolationist one to an interventionalist one and now is going back towards isolationism.

Pre-World War I under William McKinley/Teddy Roosevelt/William Howard Taft: Build the Panama canal, sail the Great White Fleet around the world, expand American colonial influence by force, enforce the Monroe doctrine. (Interventionalist)

Post-World War I under Warren Harding/Calvin Coolidge/Herbert Hoover: More isolationist, let's not get involved in another European-origin world war; heed Washington's advice. Let the League of Nations die. (Isolationist)

Post-World War II under Eisenhower/Nixon/Ford/Reagan/Bush41: Maintain the balance of Superpowers. Check the Soviet Union and the Easter Bloc. Stop the spread of communism, by force if need be. (Interventionalist)

Post Cold War under Bush43: Intervene to stop the spread of global terrorism by terrorist proto-states. (Interventionalist)

Post Global War on Terror under Trump: No foreign wars. Re-examine trade relationships to repatriate America's manufacturing base. Pivot confrontational posture towards China. (Mix of both, with isolationist bent)

The GOP follows an historical pattern: Intervention until trauma happens, then retrenches in an isolationist direction.

You may disagree with the latter, but Trump clearly recognizes that China is America's #1 threat and has always said so.