September 1, 1939: Germany invades Poland, quickly overrunning Polish border defences, and advancing on Warsaw. What if, in the lead-up to this historic moment, Winston Churchill had announced that he could not imagine any circumstances in which troops would be sent to meet the onslaught? What if he had quipped that, if Britons and Germans start shooting at one another, it would be the second world war?

Yet these are the same words with which Joe Biden abandoned the people of Ukraine to their fate, signalling to Vladimir Putin that he has a free hand to do his worst without fear...