After four years in a heightened state of alert, many people the world over now hope that sanity will return

For four years the world had held its breath, but at last came the moment to exhale. Ever since noon on 20 January 2017, when Donald Trump took the oath that made him president of the United States, the people of the planet had found themselves in a state of heightened alert: what new madness might the most powerful man on earth unleash? Within months, he had seemed to threaten nuclear war with North Korea – in a tweet directed at Kim Jong-un, he boasted that “I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!” – and there were days when it seemed rational to wonder if America, and the rest of us, would even survive four years of a Trump presidency.

Eleven minutes before noon local time, it became possible to breathe out once more. Joe Biden recited the magical incantation by which a single US citizen is transformed into the head of government, head of state and symbol of the republic. As he uttered the words “So help me God,” his hand on a thick Bible, a wave of blessed relief rippled through millions of Americans – and all those, anywhere, who had lived through the stress of the Trump era. The TV networks had helpfully shown footage of the military aide who carries the nuclear “football”, the case containing the codes required to launch the mighty US atomic arsenal, and there was comfort in knowing that that aide now answered to Biden, not the man who a few hours earlier had fled to his resort in Florida.