North Korea’s sixth nuclear test occurred within hours of the end of 10 days of US-South Korean military exercises only 30 miles from the North-South border.

Those manoeuvres with 17,500 US troops together with contingents from Britain, Australia, Colombia and elsewhere went ahead despite pleas from China and Russia not to raise the temperature any further.

The immediate response from President Donald Trump was to tweet a stream of bellicose remarks, all of which demonstrated why he is temperamentally unfit to be the “commander-in-chief” of the world’s most powerful armed forces.