Read an excerpt of The Sixth Crisis.

As the international community's concern over Iran's nuclear program grows, and UN Security Council sanctions against Iran prove to be ineffective, an apprehensive Israel gets closer to launching an attack on Iran, warn Council on Foreign Relations (CFR) Adjunct Senior Fellow Steven Simon and International Institute for Strategic Studies Senior Fellow Dana H. Allin.

In their new book, The Sixth Crisis: Iran, Israel, America and the Rumors of War, Simon and Allin write, "there is every reason to worry that, in the coming years or months, a fearful Israel will conclude that it is cornered, with no choice but to launch a preventive war aimed at crippling Tehran's nuclear infrastructure and thereby removing—or at least forestalling—what Israelis consider a threat to the Jewish state's very existence."

The authors predict that "the likelihood of Israel deciding to attack depends on Israeli assessments of U.S. and international resolve to block Iran's pursuit of nuclear weapons capability; the state of the Iranian program; the amount of time a successful strike would buy to be worth the expected risks and costs; whether Israel believes there is a clandestine program, which would lead some Israelis to conclude that an attack would buy no time at all; and the effect of a strike on U.S.-Israel relations."

Simon and Allin call this the "sixth crisis" that will reshape the Middle East and America's role in it. The book details the previous five, which are:

• The 1956 plot by Britain, France, and Israel to retake the Suez Canal from Egypt.
• The extended crisis of 1967–1973—seven years that were bracketed by two Arab-Israeli wars.
• The 1979 Iranian revolution.
• The 1990 invasion of Kuwait by Iraqi forces under Saddam Hussein.
• The September 11, 2001 terrorist attacks on the United States.

Simon and Allin warn that the "sixth crisis" would have a catastrophic impact on local stability and U.S. relations with regional actors. Should an attack happen, "air strikes against Iran's nuclear facilities might not be a limited affair: in the worst case, they could ignite a general war between Israel and Iran that would suck in the United States; drive millions of Arabs, Sunnis, as well as Shi'a, to side with Iran; reinvigorate the terrorist jihad; destroy the Israel-Palestine peace process; and decisively end America's attempt to restore its moral footing and reestablish its leadership role in the world."

To prevent these outcomes, the authors call on the Obama administration to "construct a credible regime of containment, including sufficient reassurance in the form of strengthened military protection and guarantees for Israel and Arab states." The goal of containment would be "to enforce a redline before weaponization, nuclear testing, or withdrawal from the NPT [nuclear nonproliferation treaty]."

While the authors encourage the further exploration of sanctions and mechanisms of diplomacy, "a successful regime of containment will also have to include a readiness, under certain circumstances, for U.S. military action. Washington can make clear that Iran's use of nuclear weapons would trigger an overwhelming American retaliation through whatever means were necessary to guarantee the destruction and demise of Iran's ruling regime."

The authors conclude that "the compressed coil of disaster linking Iran, Israel, and the United States is not the only problem facing the Obama administration, and it may not even be its worst problem. But Iran's defiance and Israel's panic are the fuses for a war that could destroy all of Obama's other ambitions. The sixth crisis could shape our world for many years to come."