US elections

If the vote is close, as most presidential elections are now, then the result will come down to what happens in six states: Arizona, Georgia, Michigan, Nevada, Pennsylvania and Wisconsin. This means states with a combined population of 50m people, a bit more than Spain but fewer than Italy, will choose the next president. A bigger swing in either direction could bring a few more states into play: Minnesota, New Hampshire, North Carolina, perhaps even Florida.

It is hard to overstate how important the outcome will be for America and the rest of the world. America’s next president will face some predictable problems. The trust funds that pay for Social Security and Medicare (health care for pensioners) are running out of money. Nuclear proliferation in Iran and North Korea will be in the in-tray again. And there is the looming question of Taiwan. China-watchers in the West believe there is a narrow window, which overlaps with the next presidency, during which the People’s Liberation Army would have the advantage in a conflict over the island. The president chosen in 2024 will thus be in charge in the moment of maximum danger.

Most crises, though, are of the unexpected sort. In 2016 Mr Trump campaigned on ending American entanglements in the Middle East. Less than a year later, he gave the order to launch 59 Tomahawk cruise missiles at targets in Syrian territory. The last year of his presidency was consumed by mishandling the spread of a new virus. Mr Biden’s presidency has been steadier and more successful, but the subjects that have demanded most of his attention—the bungled retreat from Afghanistan, Russia’s invasion of Ukraine and a war between Israel and Hamas—were unforeseen.