Former Mossad chief Meir Dagan recently commented on what he considers the “foolish” notion that a preventive military strike should be made on Iran’s nuclear program before it could produce weapons-grade uranium. Jeffrey Goldberg quotes one Israeli official who says, “’Dagan thinks [Israeli Defense Minister Ehud] Barak is crazy enough to strike Iran.” Goldberg, who notes that any decision to strike Iran would ultimately rest with Israeli Prime Minister Benjamin Netanyahu, interpreted Dagan’s statement to mean that an attack on Iranian nuclear facilities may be imminent. That may or not be the case, but the question really is whether or not such a preventive strike would be successful.
The success of preventive strikes on nuclear programs is a highly contentious topic. Glenn Greenwald has written on the efficacy of Israel’s attack on Iraq’s Osirak reactor in 1981 and deemed it an absolute failure because it merely drove Saddam Hussein’s program underground instead of actually ending it. On the other hand, Jennifer Rubin, writing last year in response to President Obama’s assertion that no “light switch” for stopping the Iranian nuclear program existed, alluded to the possibility that a military strike could represent such a “switch.” For his part, former U.S. ambassador to the United Nations John Bolton seemingly calls for a military attack on Iran as a matter of habit. Chairman of the Joint Chiefs of Staff Mike Mullen also weighed in last spring with his assessment that an attack on Iran was likely to merely delay their progress.
Scholars have conducted extensive research on the subject, and their assessments have generally been more in line with those of Greenwald and Mullen than that of Rubin and Bolton. Dan Reiter of Emory University has written on the subject on several occasions. He finds that preventive attacks are “generally unsuccessful” at disrupting nuclear programs, and that the Osirak attack, as is believed by many critics of preventive attacks, actually increased Saddam Hussein’s commitment to obtain nuclear weapons. Columbia University’s Richard Betts has also written about the Israeli attack on Osirak, and he too is pessimistic about the prospects of preventive attacks on Iran. As with other critics of the Iran-Osirak analogy, Betts points to the fact that Osirak was a single facility, while Iran’s nuclear program has been disbursed to numerous facilities—facilities that have also been hardened against attack and built underground as a precaution against aerial bombing. Betts also seconds Reiter’s findings about the Osirak raid not necessarily destroying the Iraqi nuclear program,
Obliterating the Osirak reactor did not put the brakes on Saddam’s nuclear weapons program because the reactor that was destroyed could not have produced a bomb on its own and was not even necessary for producing a bomb. Nine years after Israel’s attack on Osirak, Iraq was very close to producing a nuclear weapon. Had Saddam been smart enough in 1990 to wait a year longer, he might have been able to have a nuclear weapon in his holster when he invaded Kuwait.”
In light of these numerous pessimistic assessments of preventive strikes against nuclear programs, the idea persists. Now, new scholarship, from Cornell University’s Sarah Kreps and Matthew Fuhrmann of the University of South Carolina, presents a more nuanced assessment of the success or failure of various attempts to preempt nuclear weapons programs going back to World War II and the Allied efforts to destroy the German heavy water reactor in Nazi-occupied Norway. The paper—“Attacking the Atom: Does Bombing Nuclear Facilities Affect Proliferation?”—examines both wartime attacks on nuclear programs, like the allied efforts in World War II and Iranian attacks on Iraq’s nuclear program during the Iran-Iraq war, as well as peacetime, “bolt from the blue” attacks, such as the Osirak incident or the more recent Israeli strike on Syria in September 2007.
The paper bases its findings on the ability of a preventive strike to destroy certain infrastructure “chokepoints”—such as uranium production facilities and plutonium conversion facilities. Even if a program is more diffuse than the Iraqi program was in 1981, as Iran’s program seems to be, it can still be significantly damaged if these chokepoints are effectively hit. It also suggests that “indirect” mechanisms—such as foreign assistance—are affected by preemptive strikes, particularly peacetime strikes. For example, third parties are likely to be less willing to assist in construction of facilities because of fear their citizens could be killed in subsequent attacks—which likely affected North Korean assistance to Syria following Israel’s 2007 airstrike against a suspected nuclear facility—or that their reputation could be damaged from association with an “illegitimate” nuclear program. Military strikes may also discourage indigenous scientists from participating in a program that may cost them their lives, therefore starving the program of the knowledge necessary for a successful nuclear program.
Kreps and Fuhrmann push back against the notion that the Israeli attack on Osirak failed to permanently damage Saddam Hussein’s nuclear weapons program—though they are careful to note that the Osirak incident itself cannot be looked at in isolation given subsequent attacks on Iraq’s nuclear infrastructure by the Iranians from 1984 to 1988 and by the U.S. military during Operation Desert Storm. But the Israeli strike did force the Iraqis to shift their approach, and it also made outside parties less likely to cooperate. The Israeli strike also took place before the Iraqis had required the indigenous knowledge to effectively run an extensive enrichment operation. Unfortunately, this highlights their finding that “the timeframe in which strikes might be most effective is also when they would be considered the least legitimate. Anything other than preemptive uses of force (i.e., striking to prevent an imminent attack) are considered illegal under international law and the international community might be less likely to endorse attacks when it is not obvious that the target was on the verge of acquiring nuclear weapons.”
Of course, this does not necessarily mean that a bolt from the blue attack on Iran—regardless of its standing under international law—would have a lasting effect. Based on the prerequisites for success they cite in their paper, Kreps and Fuhrmann are pessimistic about the chances a military strike against Iran’s program would do much more than delay the Iranian nuclear program. Iran is already well past the threshold it needs to maintain its nuclear program even after an attack. The program relies on only marginal support from abroad, and its various chokepoints seem to either well-disbursed or hidden effectively enough that even causing major damage will likely only result in a shift in resources, not the type of shift in approach Iraq was forced to take following the attack on Osirak. “In sum,” they conclude,
given that Iran already possesses the requisite knowledge to enrich uranium—and this knowledge cannot be taken away—the best possible outcome of military force would be delaying Tehran’s ability to build nuclear weapons by around five years. Based on our survey of the historical record, it is far from obvious that military force would yield even this modest return. Policymakers should also be aware that multiple attacks against Iran might be necessary.
Israel obviously has legitimate security interests vis-à-vis Iran’s nuclear program, but any preventive military strike—successful or not—will come with political costs that the Israeli leadership must weigh. Israel is already politically isolated from much of the world and has earned condemnation in many circles due to its ongoing occupation of the Palestinians and perceived intransigence about establishing a Palestinian state. Legitimate or not, such feelings would likely be exacerbated if an Israeli preventive attack on Iran were to take place. Some might hope the United States would relieve this burden from Israel’s shoulders and undertake a military strike of its own. But the same danger applies. America is often perceived as bullying smaller states unable to match Washington’s military might. An attack on Iran is likely to fuel such perceptions and add to the narrative, sponsored by the (thankfully) deceased Osama bin Laden, that the United States is actually at war with Muslims everywhere—a hard propaganda point to dispute seeing as any military attack on Iran would be America’s fourth on a Muslim country in less than a decade. Few good options exist when dealing with Iran’s nuclear program, but it seems, if both an Iran with nuclear weapons and a preventive attack are evils, the latter might be the greater of the two.