Of the questions surrounding the defenestration of John Bolton as President Trump’s third national security adviser — Did he jump? Was he shoved? — the least interesting is the question of who will succeed him on the parapet .

It’s unlikely to matter much. Regardless of who has advised Mr. Trump on foreign affairs — generals and corporate tycoons, seasoned pros and amateurs — all have proved powerless before a zest for chaos that would have thwarted George Marshall.

Even when Mr. Trump has pursued worthy goals — trying to persuade North Korea’s dictator to give up his nuclear weapons, negotiating with the Taliban so American troops can leave Afghanistan — his mercurial, impatient, crisis-driven approach has often backfired, no matter who was advising him.

His naming of Mr. Bolton as national security adviser in March 2018 was itself an instance of Trumpian chaos. Mr. Trump wanted to pursue an end to hostilities in Korea and Afghanistan and proved wary of conflict in Iran and Venezuela. Yet he chose a proponent of belligerence who disdains diplomacy, supports allies-be-damned unilateralism and thinks bombing North Korea and Iran is the best way to neutralize their nuclear threat.