For years, black Americans saw Thomas Jefferson's pledge in the Declaration of Independence mocked by legal impediment and lingering prejudice. As the new president has often pointed out, his election does not build the colour-blind society dreamed of by Martin Luther King; still less does it perfect the union that the founders of the United States envisaged. Nonetheless it is a huge and historic advance. It stands as a challenge to other nations to live by the principles they espouse. The world, as much as the US, is not just impressed by this inauguration, it is moved – and it is right to be

One might wish that the celebrations were less encumbered by an underlying sense of crisis. History has decreed otherwise. President Obama replaces a failed predecessor and faces tests as great as any since the time of Franklin Roosevelt and the Great Depression, and they are on many fronts.

The economy is deep in recession and, as in the 1930s, it is no ordinary recession. The government has spent hundreds of billions of dollars on rescue efforts, but the US financial system is far from repaired. The danger of a prolonged slump is still real. The new president must deal with Iraq and Afghanistan, turmoil in the wider Middle East and Pakistan, tensions with Russia and the challenges of a rising China and India. He must lead an effective global response to the prospect of accelerated climate change or else the problem may soon run out of control