US presidents since John F. Kennedy have been followed everywhere by an army officer carrying a leather-bound metal Zero Halliburton briefcase. (Zero Halliburton was sold to a Japanese company in 2006, but Donald Trump hasn’t switched to an all-American manufacturer.) Inside the president’s ‘emergency satchel’, also known as the ‘nuclear football’, is a ‘black book’ containing such things as retaliatory options and the codes for launching them. The president has the power to choose any of these options and no one has the power to stop him.

The package weighs about 45 pounds and includes a radio transmitter so the presidential decisions can be communicated to whatever military forces are appropriate. It would take about thirty minutes for an intercontinental ballistic missile to strike Russia from the United States and much less if the rockets were fired from submarines. In the 1980s the Russian premier got a briefcase too, known as the Cheget. When Ronald Reagan and Mikhail Gorbachev were photographed together in Red Square in 1988 they both had their satchels with them. The two who now have the capacity to destroy civilisation are Donald Trump and Vladimir Putin.

Many years ago I had the chance to discuss Doctor Strangelove with Stanley Kubrick. Prior to writing it he had studied the game theory analyses of how nuclear war might start. He was struck by how limited the scenarios were. There was no allowance for the ‘mad major’. We did not discuss the football but knowing how Kubrick’s mind worked I can imagine how such a discussion might have gone. Is the football kept outside Trump’s bedroom at night? Did it go on his overseas trip? Was it close by when he danced in Saudi Arabia or on his visit to the Pope? It surely must follow him on the golf course? How did we allow ourselves to get into this situation and what can be done to get us out of it?