Biden rises to the moment as Ukraine makes battle against autocracy real

But it is Vladimir Putin of Russia who has made the contest more immediate and literal than anyone expected, launching a bloody invasion of Ukraine that threatens to bring down a new iron curtain in Europe.

Biden, who made no mention of Putin, Russia or nuclear weapons in his inaugural address, is discovering a truism of US history: American presidencies are often defined by crises that no one saw coming.

There appears to have been determination not repeat the blunders of Afghanistan, when allies felt blindsided as the Taliban rapidly took over and the US and western governments fled.