It's the economy, stupid, and two months before the election nobody wants to get sidetracked into discussing a peripheral issue like American foreign policy. The only people who really care about that at the moment are foreigners and the US military - and even they are not following the election with bated breath, because few of them believe that a change of president could fundamentally change the way the US relates to the rest of the world.

Although the Republicans do their best to paint Mr Obama as a wild-eyed radical who is dismantling America's defences, he has actually been painfully orthodox in his foreign policy. He loves Israel to bits, he did not shut down the Afghan war (or Guantanamo), he uses drones to kill US enemies (and sometimes, anybody else who is nearby), and he tamely signs off on a $700 billion defence budget.

How can Mitt Romney top that? He could say he loves Israel even more. In fact, he does say that, promising to recognise Jerusalem as Israel's capital. But that is purely gesture politics, since almost no other countries do, and in practice Mr Obama gives Israel almost everything it wants already.

He could pledge to spend even more on "defence" than Mr Obama, but the United States is already pouring 4.7 per cent of its Gross Domestic Product down that rat hole.

The Republican candidate faces a constraint none of his recent predecessors had: a party that really cares about the deficit. In the past three decades, it has been Republican presidents who ran up the bills - Ronald Reagan never balanced a budget, and the Bush-Cheney team declared that "deficits don't matter" - while the subsequent Democratic administrations tried to curb out-of-control spending.

Mr Romney doesn't have that option: the Tea Party wing of his party actually means what it says about both taxes and deficits. So what's left for him? Well, he could promise to kill even more of America's enemies than Mr Obama, but he can't get around the fact that it's Mr Obama who nailed Osama bin Laden.

So Mr Romney says very little about foreign policy because there is little he can say. The closest he has come to specific policy changes was an "action plan" he laid out during the Republican primaries last year. He promised to "reassure traditional allies that America will fulfil its global commitments". A couple of phone calls, and that's done.

He declared that he would move more military forces to the Gulf "to send a message to Iran," but he didn't threaten to attack Iran, or endorse an Israeli attack on Iran.

He said he would appoint a Middle East czar to oversee US support for the evolving Arab transitions. That's one more government job, but Mr Romney has even less idea than Mr Obama about where he wants those transitions to end up. He will review the Obama administration's planned withdrawal from Afghanistan. Not necessarily change it; just review it.

It's not surprising that the rest of the world doesn't care much about the US election. Most foreigners are more comfortable with Mr Obama than Mr Romney, but US foreign policy will stay the same whoever wins.

Gwynne Dyer is an independent journalist whose articles are published in 45 countries.