For the past several months, the Israelis have been threatening to attack Iranian nuclear sites as the United States has pursued a complex policy of avoiding complete opposition to such strikes while making clear it doesn't feel such strikes are necessary. At the same time, the United States has carried out maneuvers meant to demonstrate its ability to prevent the Iranian counter to an attack -- namely blocking the Strait of Hormuz. While these maneuvers were under way, U.S. Secretary of State Hillary Clinton said no "redline" exists that once crossed by Iran would compel an attack on Iran's nuclear facilities. The Israeli government has long contended that Tehran eventually will reach the point where it will be too costly for outsiders to stop the Iranian nuclear program.
The Israeli and American positions are intimately connected, but the precise nature of the connection is less clear. Israel publicly casts itself as eager to strike Iran but restrained by the United States, though unable to guarantee it will respect American wishes if Israel sees an existential threat emanating from Iran. The United States publicly decries Iran as a threat to Israel and to other countries in the region, particularly Saudi Arabia, but expresses reservations about military action out of fears that Iran would respond to a strike by destabilizing the region and because it does not believe the Iranian nuclear program is as advanced as the Israelis say it is.
The Israelis and the Americans publicly hold the same view of Iran. But their public views on how to proceed diverge. The Israelis have less tolerance for risk than the Americans, who have less tolerance for the global consequences of an attack. Their disagreement on the issue pivots around the status of the Iranian nuclear program. All of this lies on the surface; let us now examine the deeper structure of the issue.
Behind the Rhetoric
From the Iranian point of view, a nuclear program has been extremely valuable. Having one has brought Iran prestige in the Islamic world and has given it a level of useful global political credibility. As with North Korea, having a nuclear program has allowed Iran to sit as an equal with the five permanent members of the U.N. Security Council plus Germany, creating a psychological atmosphere in which Iran's willingness merely to talk to the Americans, British, French, Russians, Chinese and Germans represented a concession. Though it has positioned the Iranians extremely well politically, the nuclear program also has triggered sanctions that have caused Iran substantial pain. But Iran has prepared for sanctions for years, building a range of corporate, banking and security mechanisms to evade their most devastating impact. Having countries like Russia and China unwilling to see Iran crushed has helped. Iran can survive sanctions.
While a nuclear program has given Iran political leverage, actually acquiring nuclear weapons would increase the risk of military action against Iran. A failed military action would benefit Iran, proving its power. By contrast, a successful attack that dramatically delayed or destroyed Iran's nuclear capability would be a serious reversal. The Stuxnet episode, assuming it was an Israeli or U.S. attempt to undermine Iran's program using cyberwarfare, is instructive in this regard. Although the United States hailed Stuxnet as a major success, it hardly stopped the Iranian program, if the Israelis are to be believed. In that sense, it was a failure.
Using nuclear weapons against Israel would be catastrophic to Iran. The principle of mutual assured destruction, which stabilized the U.S.-Soviet balance in the Cold War, would govern Iran's use of nuclear weapons. If Iran struck Israel, the damage would be massive, forcing the Iranians to assume that the Israelis and their allies (specifically, the United States) would launch a massive counterattack on Iran, annihilating large parts of Iran's population.