Something very strange and a little unnerving is happening in American politics on the question of foreign policy. Everyone seems to be agreeing with one another, while adamantly refusing to admit it.

Both Barack Obama and John McCain gave big foreign policy speeches last week, and President George W Bush gave a press conference. They all spoke in clear and sometimes sweeping terms. Each of the two presidential candidates made every effort to portray the other as his nemesis and the choice between them as one of clear principle and philosophy. Obama and McCain also desperately sought to put rhetorical blue sky between them and the still fantastically unpopular president.

Look a little closer, though, and the differences between all three blur. Take Iran: Obama has famously argued that the US should deal directly with the mullahs, negotiate the nuclear question and have talks without the precondition that Tehran suspend uranium enrichment. This was a clear and vital difference, we were told only a short time ago, between a reckless, appeasing Obama and the resolute, Churchillian Bushies.

And yet last week Bush authorised William Burns, a high-level State Department official, to attend talks with Tehran’s representatives on the Iranian nuclear question. By putting oomph behind the six-power talks with Tehran, Condoleezza Rice, the secretary of state, moved the Bush administration clearly in the direction laid out by Obama. And when you see this in the context of the recent deal with North Korea, the difference between the second term of the Bush administration and its first couldn’t be starker.

What of Iraq? Obama’s position has long been that troops should be withdrawn expeditiously but with care, and that the US military should shift its emphasis towards Afghanistan and Pakistan. And, lo and behold, last week we were also told that Bush was considering accelerating the exit of Iraq troops to beef up the Afghan mission.

For good measure, McCain also gave a speech backing what he calls a “surge” in Afghanistan, with more troops and a counterinsurgency strategy in the style of General David Petraeus, the commander of US forces. In contrast with the chasm of two years ago, the rival politicians are now fighting over a somewhat narrow ravine.

So what are the key differences now? There are two, it seems to me. The first is Obama’s insistence on a 16-month timetable for withdrawal of all troops from Iraq – except a residual force of unspecified size to counter jihadist terrorism and to continue training the Iraqi army. McCain and Bush still strongly oppose any such timetable, in favour of what they call a “conditions-based” departure.

But, again, look at what Obama said last week: “We will make tactical adjustments as we implement this strategy – that is what any responsible commander-in-chief must do. As I have consistently said, I will consult with commanders on the ground and the Iraqi government. We will redeploy from secure areas first and volatile areas later.”

To blur the differences even more, Obama named Dennis Ross as a Middle East adviser. Ross worked for both the first President Bush and President Clinton and has a reputation for hawkishness, especially on Iran.

The second main difference is Obama’s dismissal of permanent bases in Iraq and the Bush administration’s and McCain’s preference for them. This is a critical debate – because it gives a sense of America’s long-term goals in the Middle East.

Does the US really want to become as deeply enmeshed in Arabia as it has been in Europe for the past half-century? Would this not merely exacerbate jihadism rather than cool it? Or does the US regard intervention in the Gulf as a temporary defensive measure, with the hope of slowly emerging from oil dependence and staying aloof from the heart of the Muslim world for the rest of the century?

Good questions. But since the decision about bases, even according to McCain and Bush, is ultimately up to the Iraqis, this difference may also be greater in the abstract than in reality. And the eerily swift decline of violence in Iraq and increasing self-confidence of the Maliki government has led the Iraqis to move US policy in Obama’s direction. No Iraqi politician wants to be a strong voice for a neocolonial presence indefinitely. If permanent bases emerge, they will do so by default.

So what are Obama and McCain now fighting over? They’re still fighting over the past, with Obama refusing to believe that the Iraq war has been anything but a massive strategic blunder, and McCain and Bush seeking retroactive justification for the whole adventure. On this, Obama has an edge - a heavy majority of Americans believe the Iraq war was a mistake, even though they are understandably divided about the next best step.

So we’re left at a deeper level with the question of presidential temperament. There is little doubt that a President McCain would have more hawkish instincts, would be quicker on the trigger than the cool, conciliatory Obama. However, Obama’s readiness to use military force in Pakistan and commitment to the Afghan war does not bespeak a Jimmy Carter-style liberalism either.

In fact, if you had to pick the most recent analogies for the style of foreign policy each man might manifest, McCain would be closer to Ronald Reagan and Obama closer to the first President Bush, whose diplomacy Obama regularly praises. And by Reagan, I don’t merely mean first-term Reagan. I mean the Reagan able to make a deal with long-time foes when he thought it could work; the Reagan able to remove forces from the battlefield if he felt they were being counterproductive.

This is not a seismic distinction. And the reason is not just that McCain and Obama represent some of the saner parts of their respective parties. It is that a mix of factors – both internal Iraqi shifts and Petraeus’s counterinsurgency tactics - have made Iraq less a question of catastrophe or quagmire and more a pragmatic question of how to withdraw as prudently as possible.

It’s amazing what a little bit of success can do for a war and a polity, isn’t it? Not “victory”, mind you, which at this point is a meaningless concept in a war whose justification was undermined within weeks of its start, but success and the pragmatic - rather than ideological - conundrums it presents.

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