Israel has signaled once again that it is weighing an attack, if all else fails, to halt Iran’s advancing nuclear weapons program as an act of anticipatory self-defense. This time, more officials in Washington and other capitals are listening. Iranian officials have repeatedly warned that Tehran will retaliate against the U.S. in the event that Israel launches a strike. The U.S. should have a clear and unambiguous policy on how it will respond if Israel undertakes legitimate action for its self-defense.

Before an Attack

To mitigate the threats posed by Iran to U.S. national security and to protect U.S. interests, the United States should:

• Recognize Israel’s right to self-defense against a hostile Islamist dictatorship that also threatens U.S. interests and regional stability. Washington should not seek to block Israel from taking what it considers to be necessary action against an existential threat. The U.S. does not have the power to guarantee that Israel would not be attacked by a nuclear Iran in the future, so it should not betray the trust of an ally by tying its hands now. Although an Israeli attack on Iran’s nuclear program would entail increased risks for U.S. interests in the Middle East, these risks would be dwarfed by the threats posed by a nuclear-armed Iran. Moreover, a nuclear Iran would induce many other Middle Eastern states to seek their own nuclear weapons. This cascade of nuclear proliferation would enormously increase the risks of a future nuclear exchange.
• Continue to deploy missile defenses to defend Israel and other U.S. allies from Iranian missile attacks. The Pentagon has already deployed an X-Band radar to Israel to support missile defense interceptors. In addition, the U.S. should make preparations to deploy or transfer to Israel the Terminal High Altitude Area Defense system and sea- or land-based versions of the Standard Missile-3 interceptors. U.S. Navy Aegis-class warships should be deployed to protect Israel and other threatened U.S. allies against a possible Iranian ballistic missile attack. The Obama Administration should also offer to further deploy land- or sea-based missile defense systems in the greater Persian Gulf area with the members of the Gulf Cooperation Council—the alliance formed in 1981 by Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates to provide collective defense against Iran and other threats.
• Hold more frequent missile defense exercises with Israel and other nations. The Juniper Cobra joint missile defense exercises conducted with Israel in 2009, for example, involved up to 2,000 personnel and some 17 U.S. Navy warships that simulated a joint defense against a missile attack on Israel from all directions. Such exercises provide valuable hands-on experience necessary to maintaining an effective overall missile defense system.
• Enhance deterrence against Iranian attacks. To deter Iran from following through on its threats to attack American targets in response to an Israeli preventive attack, the Obama Administration should make it clear to Tehran beforehand that such attacks would make a bad situation much worse for the regime. Since the Islamist dictatorship’s highest priority is its continued domination of Iran, Washington should privately warn the Supreme Leader that if the Ahmadinejad regime launches attacks against U.S. targets, the U.S. would respond with devastating strikes against not only Iran’s military and nuclear targets but regime leaders and the institutions that keep the regime in power—particularly the Revolutionary Guards, intelligence agencies, and internal security forces.
• Warn Tehran that if it takes action to disrupt Arab oil production in the Persian Gulf or attacks American targets, the U.S. would prevent any Iranian oil from being exported through a naval blockade. Communicating this ahead of time could help to deter Iran, as the loss of oil income would be a major blow that would threaten the survival of the regime.

If an Attack Occurs

• Respond robustly to any Iranian military or terrorist attack against American targets. If Tehran attacks the U.S. people or property, then Washington should respond in a forceful way that leaves Iran in a much worse situation. The Pentagon should activate contingency plans for air strikes against Revolutionary Guard bases, ballistic missile production and launch facilities, air bases, naval bases, and Iran’s nuclear weapons program infrastructure. If Iran persists, then the U.S. and its allies should launch air strikes on Iran’s top leaders and impose a naval blockade on Iran’s oil exports. No Iranian regime could survive long without oil export revenues, which furnish the bulk of Iran’s government income.
• Defend against and attack Hezbollah and other Iranian terrorist surrogates. Tehran is likely to use Hezbollah to attack American targets around the world and possibly inside the U.S. The Pentagon should target Hezbollah bases and leaders and cooperate with other U.S. government agencies and U.S. allies to uproot Hezbollah drug smuggling, money laundering, and other fundraising activities. Tehran should also be clearly warned that it will be held responsible for any surrogate terrorist attacks.
• Veto any Security Council resolution that does not acknowledge Iran’s provocations and continued defiance of U.N. resolutions. The Ahmadinejad regime has frequently stoked tensions with Israel by threatening to “erase Israel from the page of history” and a constant stream of other threats that are tantamount to incitement for genocide. Ahmadinejad’s denial of the Holocaust while building weapons for another possible holocaust was unwisely provocative as well. Israel, whose unofficial motto is “Never again,” is especially sensitive to such bellicose rhetoric, particularly when it is backed up with concrete signs that Tehran is developing a nuclear capability and the missiles to deliver it. Washington should point out to members of the Security Council that are critical of the veto that the U.N.’s weak and ineffective response to Iran’s nuclear program helped to sow the seeds of conflict with Israel.

Be Prepared

The U.S. should stand shoulder to shoulder with Israel in confronting Iran’s growing nuclear menace. If Jerusalem decides to exercise its right of self-defense, then the U.S. and its allies should support that decision, not condemn it. The brutal dictatorship in Tehran has been given ample warning that its longstanding violations of its legal obligations under international treaties will have a progressively heavy cost, yet it defiantly continues to enrich uranium, issue threats, and order terrorist attacks, including one plot to bomb a restaurant in Washington, D.C. If Iran is willing to risk such an attack before it gains nuclear weapons, what threats is it likely to pose after it attains nuclear weapons? The U.S. and its allies cannot afford to find out.

James Phillips is Senior Research Fellow for Middle Eastern Affairs in the Douglas and Sarah Allison Center for Foreign Policy Studies, a division of the Kathryn and Shelby Cullom Davis Institute for International Studies, and James Jay Carafano, Ph.D., is Deputy Director of the Davis Institute and Director of the Allison Center at The Heritage Foundation.