The world woke yesterday to an overwhelming sense of relief at the re-election of Barack Obama.

Not because everyone loves him, or because everyone loathes Mitt Romney, but because it means that existing international relationships can carry on.

At a time of such economic fragility, the last thing the world needed was a settling in period - 18 months or more - for a new man in The White House.

But the big challenge facing President Obama is how he will be able to make progress given that America has voted for the status quo which has strangled any real momentum during his disappointing first term.

We have the same president with a fresh mandate. But we also still have a Republican House of Representatives, a Democratic Senate, and a popular vote split down the middle.

It is hard to see how America can move forward, and take the rest of the world with it, when it is bound by a system which is pulling in different directions?

Four years ago, Barack Obama made history as the first black president of the United States. But he will have earned a more pronounced place in history if he can inspire compromise and unite a deeply divided country.