In their second terms, many American presidents decide to strut the global stage. Richard Nixon had his overture to China. Bill Clinton became obsessed by the Middle East peace process. George W. Bush was embroiled in the Middle East war process.
It is clear that Barack Obama intends to be an exception to this rule. In his second inaugural speech, the president devoted very little time to the outside world. It is clear that he wants his legacy to be domestic. Gun control, immigration reform, fiscal balance, economic recovery - these are his priorities.
In foreign affairs, it looks as though Obama’s biggest goal is to be the president who brought the boys back home. He declared firmly that “a decade of war is now ending”. He concluded the conflict in Iraq in his first term, and plans to pull out of Afghanistan in his second.
Obama’s actions speak as loudly as his words. He intervened only reluctantly in Libya, and America’s arm’s-length attitude to the conflict gave birth to the now-famous phrase “leading from behind”. The president’s decision to nominate Chuck Hagel to run the Pentagon suggests that he remains instinctively anti-interventionist.
Hagel opposed the Libyan operation and the Afghan surge — and he has made clear he is highly sceptical about a military strike on Iran. The fact that some see the current mess in Mali as an indirect product of the toppling of Muammer Gaddafi will only strengthen the caution of the Hagelians, who argue that even successful interventions often have dangerous, unforeseen consequences.
The effects of a less interventionist US could be dramatic for the rest of the world. European leaders, who spent much of the Bush years complaining about American activism are now, ironically enough, worrying about the opposite problem - a US that sits on the sidelines and lets problems fester.
Syria is exhibit one. America’s reluctance to intervene there is palpable - and, without the US to prompt and support them, the much weaker Europeans are certainly not going to get involved.
Yet the situation is deteriorating fast, in both strategic and humanitarian terms. There are now more than 60,000 dead, and jihadist forces are gaining ground among the opposition to President Bashar Al Assad. The embarrassing truth is that Qatar is exerting more influence on the ground than the US or Nato.
Syria is an uncomfortable reminder that geopolitics abhors a vacuum. If the West is unable to help restore order in an anarchic situation, other forces will emerge - whether it is jihadists in Mali or a resurgent Taliban in Afghanistan.
It suits America that a European power should lead the Malian operation. But the US has not authorised any military support for the French. If France runs into trouble, the Americans will remain reluctant to deploy military assets to help them. (Some might recall that shoring up a floundering French military operation was how America got sucked into Vietnam.)
France might look instead to its EU partners, but defence budgets are shrinking all over Europe — as the Americans never fail to point out. So it is possible that the West may find that it is simply unable to mobilise the resources to deal with jihadist threats in north and west Africa.
It is already clear that in the second Obama term, the Pentagon budget will fall — and America will seek to cut back rather than expand its foreign engagements.
As a result, Obama faces accusations that he is organising a retreat from American greatness. But he has a perfectly coherent response to this charge. The foundation of American strength in the world is the power of its domestic economy. Unless he puts ‘nation-building at home’ first, US global leadership will be based on rotten foundations. Besides, Americans are sick of foreign wars and want the president to improve their lives at home.
The problem with Obama’s ambition to concentrate on economic and social reform is not that it is ignoble, but that it may be unrealistic. It would be highly convenient if the world would calm down for a while. Yet international crises are inevitable - and even a cautious, non-interventionist, administration can be dragged in.
In recent years, it has been the Middle East that has tended to throw up such events - and Iran remains an obvious candidate for the president’s second term. But the biggest and most dangerous crisis of them all could be building in east Asia — where war talk between Japan and China has grown to dangerous levels in their dispute over the Senkaku-Diaoyu islands.
The US has already sent a couple of emergency missions to try to calm things down - but has also made clear that a Chinese attack on the islands would trigger America’s defence guarantee to Japan.
For Obama - dedicated as he is to social reform at home, and to ending foreign wars - it must seem almost unthinkable that he could yet end up leading America into a conflict with China. But the risk, although small, is there.
The president might recall that one of his heroes — Franklin Roosevelt — was also elected to save the American economy in a time of crisis, and spent his early years in office pushing through great social reforms.
Yet FDR ended up as a wartime president. It could happen to Obama, too.