On August 6 1945, 16 hours after the nuclear bombing of Hiroshima, President Harry Truman declared from the White House that “the force from which the sun draws its power has been loosed against those who brought war to the Far East”. If the Japanese did not agree to the terms of surrender, warned Truman, “they may expect a rain of ruin from the air, the like of which has never been seen on this earth”.

Seventy years on, there is more than an echo of that apocalyptic threat in President Donald Trump’s warning to North Korea, delivered from a New Jersey golf club in peacetime, that it would face “fire and fury like the world has never seen”.

If there is any comfort at all to be had in this episode, perhaps it is that the re-purposing of Truman’s words implies a policy process, and some historical awareness, rather than glib presidential improvisation after 18 holes.