Former Trump adviser John Bolton (Image: Flikr/Gage Skidmore)

Overnight we've seen yet another departure from US President Donald Trump's fantastically porous cabinet: national security adviser, war enthusiast and animated Mark Twain wax figure John Bolton has been fired... or quit (Trump has said he asked for Bolton's resignation, while Bolton contends he offered the resignation himself). Whatever the case, we're set for a fourth person to fill the national security adviser role in three years.

Of course the combination of the hawk Bolton and the isolationist Trump was always an odd fit.