When Barack Obama was still campaigning for the presidency first time around, he was unsettled to receive his first top-secret security briefing from US intelligence chiefs.
"You know, I've been worried about losing this election," he told his briefers after learning of the crises waiting on the desk for the incoming president. "After talking to you guys, I'm worried about winning this election," he half-joked, according to the author Bob Woodward.
Now that he has won a second term, the weight of presidential responsibility again presses on him, and the most urgent threat he confronts is not terrorists from afar but the terrorists who sit two kilometres down the road.
It's a dangerous cell called the US Congress, and it threatens to blow up the US economy, and its credibility and its status as a strong and responsible power. Obama has 54 days to strike a budget deal with Congress and if he can't, the US will topple over the "fiscal cliff" into a new recession, dragging the world after it.
The cliff is a legislated bundle of government spending cuts and tax increases totalling $US608 billion that are due to take effect automatically on January 1.
Wayne Swan in Washington yesterday said it would have a "dramatic impact and flow-on effect to the global economy", including Australia's. A group of 15 of America's biggest financial institutions has warned it would be "very grave".
Because while the Democrats have recaptured the White House and the Senate, the Republicans have held onto their majority in the House of Representatives.
The divided Congress has long proved incapable of negotiating in good faith on the budget. And the election will not solve the problem: "It doesn't mean everyone will sing Kumbayah together," says the political commentator Charlie Cook.
But won't the Republicans be chastened by Mitt Romney's defeat? Perhaps. But in the civil war that will now unfold in the Republican Party, it's equally possible it will conclude that Romney failed because he was not radical enough, and become even more intransigent.
If the US goes over the "fiscal cliff", it will leave a weaker America confronting the rising great power, China: "Obama has a big problem [with China],'' says Mike Green of the Centre for Strategic and International Studies and formerly the top Asia official under George W. Bush.
"The key task for Obama is to reassure China that the US is not trying to block China's rise, but do it without appearing weak."
The US "pivot" to Asia, embodied by the permanent new marines deployment to Darwin, will continue to be central to that task, but with a shrinking US military budget. And without Hillary Clinton, who is stepping down next year as Secretary of State.
"The energy and commitment to Asia might change," says Green, "because a lot of people can't see who could replace her that'd bring the same level of energy and discipline" to the Asia 'pivot'.
US primacy is under greater challenge than at any time since the Soviet Union threatened it with nuclear annihilation. Welcome back to work, Mr President.