Last week, shortly after the third and final presidential debate, the one ostensibly devoted to foreign policy, I got a call from a major Romney supporter (not a Sheldon Adelson-sized donor, but still someone with throw-weight) who sounded worried about his candidate’s position on the Iranian nuclear threat.

You will recall that Mitt Romney, the Republican candidate, seemed to be auditioning for the role of President Barack Obama’s national-security adviser during the debate, more or less agreeing with the president on everything from Iraq to Afghanistan to Syria, and emphasizing his desire for a peaceful, negotiated resolution to the Iranian crisis.

“It is also essential for us to understand what our mission is in Iran, and that is to dissuade Iran from having a nuclear weapon through peaceful and diplomatic means,” Romney said.

The Republican nominee has spent his entire campaign hammering Obama as a squish on Iran. The arguments are familiar by now: Obama is naive; Obama writes mash notes to the supreme leader; Obama is ambivalent about sanctions; and most of all, when the moment of decision arrives, Obama will accede to Iran’s nuclear capability rather than launch a military strike. Romney, by contrast, has positioned himself as the candidate who won’t flinch if the time comes to order the bombers into the air.

New Tone

Was Romney going soft? my caller asked. Was his candidate Etch-A-Sketching away from his commitment to stop Iran from acquiring nuclear weapons? This donor wasn’t the only one flummoxed by the apparent shift. I have been told that Senator Lindsey Graham of South Carolina, a Romney supporter and possibly the hardest among the hard-liners on Iran (he said recently the “time for talking is over”), expressed frustration with senior campaign officials over Romney’s new tone.

I, too, was perplexed. Not about debate tactics -- it doesn’t take a genius to understand that most Americans aren’t eager to open a new front in the seemingly endless war against Muslim militancy -- but about whether Romney had been head-faking us the whole time. After all, it isn’t always easy to identify his fixed positions on a range of subjects.

So I e-mailed Romney some questions. The first couple were simple: Has your stance softened? Has your thinking shifted on the question of whether negotiations with Iran could bear fruit?

He e-mailed back a lengthy response. Here are the crucial bits: “I have always talked about the diplomatic process,” he wrote. “I will not rule out diplomatic options, so long as we would not be rewarding bad behavior and so long as the Iranian leadership was truly cornered and ready to change its behavior. A crumbling economy is not enough. Because even with a crumbling economy, the Iranian leadership is still racing towards a bomb right now.”

Romney went out of his way to suggest that the Obama administration plans to spring some sort of late-November surprise on America’s Middle East allies, citing a recent New York Times report that Iran and the White House had agreed to face-to-face negotiations after the election (a report denied by the White House). “Our closest allies, like Israel, will not learn about our plans from the New York Times,” Romney wrote. “And I’ll be clear with the American people about where I’m heading. I won’t be secretly asking the Ayatollahs for more flexibility following some future election.”

Biggest Mistake

He also denied that his new emphasis on negotiations means that he would accept less than a complete halt to Iran’s nuclear work: “To be clear, the objective of any strategy will be to get Iran to stop spinning centrifuges, stop enriching uranium, shut down its facilities. Full stop. Existing fissile material will have to be shipped out of the country.”

I asked Romney to name the biggest mistake he thinks Obama has made on Iran. “President Obama has sent the Ayatollahs mixed messages throughout the past four years,” he wrote. “That’s why he has lost credibility on the negotiating track. Round after round after round of talks and nothing to show for them. Iran continues to race to a nuclear weapons capability and continues to become more brazen in its support of terrorism around the world, including a terror plot in Washington, D.C.,” a reference to a thwarted plot, hatched in Tehran, to assassinate the Saudi Arabian ambassador to the U.S.

Romney went on: “What do I mean by mixed messages? In the first year of his administration, the President said he would sit down with Ahmadinejad without pre-conditions, and President Obama deliberately remained silent during the Green Revolution, signaling to the Ayatollahs that Iran’s dissident movement would not have America’s support. President Obama also pursued a policy of creating ‘daylight’ -- his word -- between the U.S. and Israel. And through the end of the third year of his administration, the president fought congressional efforts -- bi-partisan congressional efforts -- to pass crippling sanctions on Iran’s Central Bank. This all happened against the backdrop of the president’s top advisors and cabinet secretaries broadcasting the risks of the military option, therefore conveying to Iran’s leadership that the threat is simply not real. Add all of this together, one can understand why Iran’s leaders are not taking the United States very seriously these days.”

A Caricature

Some of this is campaign bluster. Decision making inside the Iranian regime is too opaque for us to know exactly what the supreme leader thinks of Obama. And the Romney campaign’s portrayal of Obama’s policy is a caricature; Obama has never been as naive about Iran as Republicans have alleged.

Romney’s more potent criticism of Obama has more to do with statements made by Obama’s underlings. It is true, as Romney wrote, that administration officials have discussed publicly the risks of an American (or Israeli) attack on Iran’s nuclear facilities. There are risks, of course -- potentially catastrophic ones -- of attacking. But it doesn’t help the American negotiating position to publicly telegraph to the Iranians these sorts of doubts.

Which brings me to a central contradiction in this looming crisis: Obama, the putative appeaser, is more likely than Romney to use military force against the regime’s nuclear sites. As a liberal Democrat, he will face less opposition, and find more international acquiescence, for such an attack, and a study of his record on the subject of non-proliferation shows him to be preoccupied by the threat posed by Iran.

Romney, on the other hand, isn’t the warmonger the Obama camp makes him out to be. He has never closed the door on the idea of negotiations, and his answers in the debate, and in our e-mail exchange, are consistent with earlier statements. In Jerusalem in July, he said, “We should employ any and all measures to dissuade the Iranian regime from its nuclear course, and it is our fervent hope that diplomatic and economic measures will do so.”

Moreover, as a Republican governing in the shadow of President George W. Bush, Romney will also have a more difficult time mustering support for an eventual strike. But if he calibrates his approach well -- if the Iranians are led to believe that he might just be crazy enough to strike -- he would find it easier to force the regime to the negotiating table. In other words, if he becomes president, it may be in the American interest for Romney to be privately reasonable and publicly unreasonable.

As we saw in last week’s debate, that’s a very hard line to walk.

(Jeffrey Goldberg is a Bloomberg View columnist and a national correspondent for the Atlantic. The opinions expressed are his own.)

To contact the writer of this article: Jeffrey Goldberg at goldberg.atlantic@gmail.com

To contact the editor responsible for this article: Timothy Lavin at tlavin1@bloomberg.net