As diplomats prepare for more negotiations, the prospect of a military attack on Iran’s nuclear program looms again -- fueled by supreme leader Ayatollah Ali Khamenei’s Feb. 7 statement that “talks will not solve any problems.” That makes a cost-benefit analysis of airstrikes all the more urgent.
We at Bloomberg View don’t claim clairvoyance on this -- even top Israeli officials disagree on the value of airstrikes.
Still, gaming out the consequences sheds light on how much flexibility and patience the U.S. and its allies should show when they meet Iranian negotiators on Feb. 26 in Kazakhstan. Both U.S. and Israeli officials have ruled out a policy of containing a nuclear-armed Iran. If we take them at their word, there will be no third way between a settlement and military action.
For this exercise, we made two assumptions. First, that both Israel and the U.S. have the capacity to carry out airstrikes in Iran with acceptable losses to their own forces. Second, that the destruction of Iran’s nuclear facilities would set the country’s uranium enrichment program back by two or more years, but could not -- short of a U.S. invasion or regime change in Tehran -- end it.
We broke the potential costs of an attack into four basic elements: casualties, expulsion of international nuclear inspectors, military retaliation and diplomatic fallout. How many Iranians, including civilians, would die in a strike is the most important to assess, not just for moral and humanitarian reasons, but also because the scale of losses may determine other costs -- for example, the levels of Iranian retaliation and of continued international support for sanctions.
Several studies have attempted to estimate fatalities from an airstrike. The best known, produced in September by the University of Utah and Khosrow Semnani, a former U.S. hazardous waste magnate, predicts total fatalities of 3,500 to 5,500 people working at the three nuclear sites most likely to be targeted, and about 12,000 to 70,000 civilians in the surrounding areas.
Killing 70,000 Iranian civilians in a pre-emptive strike to eliminate an unrealized Iranian nuclear weapon would have severe consequences. Iranians would probably rally around the government, demanding retaliation in kind and a nuclear deterrent against future attacks. Few Muslim leaders in the Middle East would be able to endorse the slaughter, damaging U.S. interests. Mass casualties might cause the international consensus for the sanctions regime against Iran to collapse.
So what of those numbers? The Semnani study assumes, first of all, that neither Israel nor the U.S. would attack the nuclear power plant at Bushehr, one of 16 Iranian nuclear facilities that the Vienna-based International Atomic Energy Agency has documented. Bushehr is not considered a weapons risk, and no state has ever bombed a working nuclear plant, because of the potential for huge civilian casualties -- think of Chernobyl. Among the cities downwind of Bushehr are Abu Dhabi, Doha, Dubai and Manama, Bahrain -- all home to U.S. allies.
That leaves four major known nuclear sites to target. The main underground uranium enrichment facility at Natanz is penetrable. The study estimates 1,000 deaths there. It also predicts that 1,700 to 7,000 civilians unconnected to the plant would die in the surrounding area from plumes of toxic chemicals released.
The heavy water reactor at Arak is not operational and could therefore be destroyed without significant risk of releasing radioactive materials, but some of the 500 staff would die. The study makes no casualty estimate for the Fordo facility near the holy city of Qom because it is unclear whether even U.S. bunker-buster bombs could penetrate the 80 to 90 meters (260 to 295 feet) of rock under which the facility is buried.
The main unknown in terms of civilian fatalities concerns Isfahan, the former capital of the Persian empire and Iran’s third largest city. That is where the IAEA says Iran has produced most of its 550 tons of hexafluoride, or UF6, the feed stock for uranium enrichment. If large amounts were still stored at the site, if they were heated sufficiently in an explosion, if they were aerosolized and released into the atmosphere from inside a collapsed bunker in sufficient quantities, and if the wind blew in the right direction, the study estimates that not only would most of the approximately 2,000 people who work at the site be killed, but anywhere from 12,000 to 70,000 civilians would die in Isfahan.
That last number is highly suspect. The circumstances needed to vaporize enough UF6, and for the toxic chemicals to reach the city of Isfahan, are simply improbable. The figure is useful only as a worst-case scenario.
The more important question for military planners may be the scope of the strike. If they want to hit only nuclear facilities and can suppress Iran’s air defenses electronically, collateral damage will be lower. If they also want to strike dual-use factories, air defenses, command and control sites, mobile rocket launchers and the Iranian Revolutionary Guards Corps (in order to damage Iran’s ability to retaliate), then many of the targets will be in populated areas. Higher military and civilian casualties would result.
Israel’s recent attack on a suspected arms convoy inside Syria suggests it might choose the less extensive option. Recent history, however, suggests a U.S. attack would aim to suppress air defenses and strike harder at Iran’s military.
So notwithstanding some exaggerated estimates, the death toll from airstrikes could easily climb into the thousands. At the same time, the more U.S. and Israeli military planners attempt to reduce civilian deaths, the less effective the attack will be in terms of destroying Iran’s nuclear infrastructure and ability to retaliate.
A second issue concerns the potential cost of losing international nuclear inspectors in Iran. IAEA inspectors have served an essential purpose, ever since 2003, in confirming intelligence provided by the U.S. and about 10 other countries on Iran’s once covert nuclear program. Because they track Iran’s nuclear material, these monitors also serve as the early warning system for determining any Iranian breakout to enrich uranium to weapons grade. The IAEA still maintains that Iran hasn’t begun enriching fuel to that level.
After an attack, Iran would probably withdraw from the 1968 Treaty on the Non-Proliferation of Nuclear Weapons and kick out these international inspectors. In the first instance, their loss might not mean much. At least at Natanz, Isfahan and Arak, only rubble would remain to monitor.
The loss of inspectors at Bushehr could be significant if the Iranians decided to develop the technology to reprocess spent fuel from the plant into weapons-grade fuel -- an expensive and difficult, though not impossible route. Similarly, should the Fordo bunker survive, Iran could enrich fuel to weapons grade unwatched. Since coming on line, this facility has tripled Iran’s production rate of the 20 percent enriched uranium that is most worrying.
The third potential cost is retaliation. The more devastating the attack, the more probable that Iran might try to block shipping in the Strait of Hormuz, gateway to about 20 percent of all traded oil; attack Israel directly or via Hezbollah or Hamas; hit U.S. and allied targets, civilian and military, around the world; and undermine U.S. interests in Afghanistan, Iraq or Syria. Attempts to predict this kind of fallout are invariably wrong, but at the higher end they include fears of driving up oil prices, damaging the already fragile global economy and triggering regional destabilization.
Finally, there would be the possible diplomatic costs. The more convinced U.S. allies in Europe and elsewhere are that every other avenue is exhausted and that Iran is actually developing nuclear weapons, the more likely they are to accept military strikes and continue sanctions afterward. This is important, remembering that diplomacy, sanctions and sabotage have slowed Iran’s nuclear progress considerably over the past decade, including a suspension of enrichment from 2004 to 2006. It will take longer for Iran to rebuild its nuclear program after airstrikes, if the financial and economic sanctions remain effective.
Given that the probable benefits of military action are limited and the costs so uncertain, the Obama administration is right to try again for a negotiated settlement with Iran. The outlines for a deal have long been clear: maximum Iranian transparency to international inspectors, a clear explanation of evidence suggesting that Iran has been trying to weaponize, transfer of all 20 percent enriched uranium outside the country, agreement to enrich uranium only to 3.5 percent, and limitation of fuel production to levels consistent with Iran’s civilian needs. In exchange would come the staged lifting of sanctions.
The U.S. and its allies must not bend on these requirements, and they can’t afford to be still negotiating when Iran declares it already has the bomb. Khamenei’s stiff words this week are a reminder of the political obstacles negotiators face, and the need for the regime in Tehran to claim victory and save face with any deal it can plausibly accept.
At the last round of failed nuclear negotiations, the U.S. and its allies offered Iran only marginal sanctions relief, such as spare parts for civilian aircraft, in exchange for concessions. Due to the mistrust Iran’s negotiators have earned, that caution wasn’t surprising, but it was a mistake. The limited benefits and uncertain costs of airstrikes, together with a closing window for talks, mean that international negotiators should go significantly further in offering Iran the staged removal of sanctions that would relieve the pressure on their economy, if they take the required steps.
If it comes to pre-emptive military action, the last diplomatic offer Iran rejects needs to be a generous one.
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