John Bolton is to leave the White House after a tempestuous time as the president’s third National Security advisor, it was announced on Tuesday. Exactly whether he is jumping or was pushed is still somewhat in doubt; while Trump claims that he fired him, Bolton rejects that framing as “flatly wrong,” claiming he resigned.

So far, so business as usual for the reality TV show presidency. The circumstances of his departure appear to have been sudden, but this moment was a long time coming. The two have regularly clashed over foreign policy matters; Bolton is a gung-ho neocon interventionist who was one of the core architects of the Iraq war and who has called for bombing Iran and nuking Pyongyang.

Trump, as far as he can be thought to have any ideological principle, is instinctively an isolationist who campaigned hard against entangling American troops in foreign wars. Self-conceived as a deal-maker, his threats of “fire and fury” against North Korea were counterbalanced by an almost childlike desire to be liked, even – especially – by despots like Kim Jong Un.

The most likely flashpoint is Trump’s bizarre out-of-the-blue public cancellation on Saturday of a purportedly secret Camp David summit with Taliban leaders. Exactly what happened there is also still unknown, but certainly the timeline would imply that whatever happened – or, given that this is Trump we’re talking about, the media coverage of the resulting cancellation – represented the last straw that broke the back of the already tense relationship between the two.

Another factor was probably the mooted possibility of an upcoming meeting between Trump and Iran’s President Hassan Rouhani. Trump’s expressed interest in meeting with the Iranian leader represents utter anathema to Bolton’s entire worldview, so it is hardly surprising that he should choose to leave now. Reading the tea-leaves, this is probably an example of Trump doing his classic “you can’t quit, I fire you” schtick.

Whatever the reason, Bolton’s departure will come as a relief to most of the foreign policy world, who have long considered the walrus-moustached neocon as one of the greatest dangers to world stability because of his near-fetishistic desire to solve almost every problem with the application of extreme military force. His departure may set the doomsday clock back a little, at least.