A common view among strategists and political analysts is that the US will be held responsible by Iran and much of the Muslim world. Tehran is expected to use the relationships it has carefully cultivated with militants in Iraq and Afghanistan to lash out at US troops, and some say it could provide fighters in Afghanistan with the surface-to-air missiles they crave.
"There are segments of the [Iranian] regime, parts of the military apparatus especially, that will welcome an attack, the heightening of tensions and even confrontation," says Kaveh Ehsani, a political scientist who studies Iran at DePaul University in Chicago. "Their strategy to react to this is to export conflict – to Afghanistan and Iraq and Lebanon and Gaza… they’ll raise hell anywhere they can, like in Saudi Arabia."
But how big the Iranian reaction would be remains an open question. More US soldiers would die, that much is almost certain. But how many is unclear. And while Iran can bottle up tankers in the Strait of Hormuz and drive up world oil prices, or encourage Hezbollah in southern Lebanon to rain missiles on Israel, analysts are divided on whether the country will take the plunge.
US response could be far more threatening than Israeli one
Wayne White, former deputy director of the Middle East desk at the State Department's Bureau of Intelligence and Research, says a there's a complex web of calculations being made by both the Israelis and the Iranians, and that Iran may show restraint in the wake of an attack, not wanting to be drawn into a conflict that could threaten the Islamic revolution.
"The Iranians might also appreciate that if they up the ante ... there could be more blowback on them," he says, pointing out that a dramatic Iranian attack on US interests, or a precipitous withdrawal from the Nuclear Non-Proliferation Treaty and UN nuclear monitoring could provoke a US response far more threatening to Iran than the limited strike Israel is capable of.
He says some retaliation against both Israeli and US interests is inevitable, "but not in such a visible form, such a dramatic shift that could be immediately placed upon them. They may be cunning about this, knowing that they still have a lot of their [nuclear] program, and not give us a pretext to wade into the situation and take what they have left.... the thing they really fear most is that huge attack from the United States that could, in the end, involve several thousand sorties against a great array of targets."
Why might Israel attack Iran, which insists its nuclear program is for purely peaceful purposes? It's no secret that Israel is deeply skeptical that harsh new sanctions on Iran over its nuclear program will prevent it from progressing. Israel also dismisses Tehran's assurances of peaceful intent out of hand.
Israeli leaders like Prime Minister Benjamin Netanyahu view Iranian President Mahmoud Ahmadinejad as an anti-Semitic madman who wouldn't be deterred by the risk of a massive nuclear retaliation from Israel, the region's only nuclear power. Often Israeli rhetoric compares a possible Iranian nuclear bomb with the Holocaust.
Mr. Ehsani says those sorts of fears are clouding Israeli and American strategic thinking. Both are "obsessed with the nuclear program at the expense of long term, geostrategic thinking about Iran," says Ehsani. "If everything you’re doing in terms of setting up your pieces on the chess board is to stop them from developing their nuclear program, which Iran is pursuing because of concerns about regime survival, then you've got a sort of vicious circle that could backfire."
Intentions and capabilities
The actual outcome of an Israel strike is likely to be murky. Israel's successful attacks on an unfinished Syrian nuclear reactor in 2006 and Iraq's Osirak nuclear facility in 1981 (which Iran had tried to and failed to destroy with jets of its own the previous year) are sometimes held up as models. But those were single sights, much closer to Israel and above ground.
Iran has 17 known nuclear sites and has placed many of its key facilities deep below ground, so deep that there are doubts that even "bunker buster" bombs could destroy them. But "if there’s one tunnel complex that we’ve discovered, there’s probably seven or eight we haven’t," says White. "They've been preparing for this for a long time."
And an attack wouldn't be easy: Long flights over Saudi Arabia, Iraq, or Turkey, limited time over their targets, and a need to hustle home to deal with possible Hezbollah retaliation are just a few of the problems.
As Steven Simon, a senior fellow for the Council on Foreign Relations, put it in a briefing on the odds of an Israeli strike on Iran last winter: "Israeli officials are aware that no conceivable Israeli strike could completely eliminate the nuclear threat posed by Iran and that an attack might only intensify longer-term risks as Iran reconstituted covertly, advancing an argument long made by counterterrorism officials that any effort to counter Iran’s nuclear challenge is going to be like 'mowing the lawn.' "
Col. (ret.) Pat Lang, a former head of the Middle East desk at the Pentagon's Defense Intelligence Agency, writes on his blog that a 50 percent chance of an Israeli attack is "about right" though he cautions of the consequences for US interests. "Goldberg doesn't think that the US would eventually be drawn into such a war? That is foolish. The escalation ladder that would be climbed would be likely to include attacks on US forces and a strike on Israel would be probable from some quarter. That would create a political situation in which US entry into the war would be likely."
Repercussions and triggers
That's an outcome US officials are well aware of, and at least one reason that a unilateral Israeli attack, something the Obama administration opposes as the Bush administration did before it, would strain US ties.
But if Netanyahu becomes convinced that sanctions aren't working and that the US is unlikely to lead an attack, Goldberg argues the Israelis "will state that they believe they have a reasonable chance of delaying the Iranian nuclear program for at least three to five years. They will tell their American colleagues that Israel was left with no choice. They will not be asking for permission."
White predicts that the strains on the US relationship with Israel would be manageable since "the US population is well inclined to Israelis and has a dismal view of Iran."
"The US doesn’t want to do this at all, and doesn’t want them to light the fuse, either," he says, "because it would be presumed that we gave them the green light. This is an unfortunate belief in the Middle East – it just isn't true. When the Israelis wish to do something exceedingly dramatic like the [Osirak] raid in 1981, they don’t tell us anything at all."
He says he would expect Israel to carry out a strike on Iran if it received intelligence about a specific site or nuclear progress that they viewed as "alarmingly actionable." He adds that there is no strategic hesitation "except for the difficulty of the mission, because they believe Israel will survive the bulk of the blowback.... In the long run, I’m alarmed. In the short run, I think the Israelis don’t want to do this."
At times, the US military establishment has appeared less eager for a confrontation than members of the Obama administration, who have repeatedly said that "all options are on the table" when asked about what the US might do if sanctions don't make a dent in Iran's nuclear program.
Admiral Mike Mullen, at the World Leaders Forum at Columbia University in April, said that the "unintended consequences" of an Israeli attack on Iran would "be substantial in an area that's so unstable right now. We don't need more of that." He even appeared ambivalent about which was worse -- a nuclear armed Iran or a war with Iran.
"What we need is engaged political and diplomatic leadership from around the world to make sure that that doesn’t – that neither one of those things happens. And I don’t believe – I think Iran having a nuclear weapon would be incredibly destabilizing. I think attacking them would also create the same kind of outcome."
(This article was edited after posting to correct the name of The Atlantic magazine).