Iran with Nuclear Weapons: Anticipating the Consequences for U.S. Security

Last updated December 20, 2013

The United States opposes Iran’s efforts to develop or otherwise acquire nuclear weapons. According to the March 2006 National Security Strategy, “the proliferation of nuclear weapons poses the greatest threat to our national security,” and now that North Korea has explicitly crossed the nuclear threshold, U.S. efforts will likely focus more than ever before on preventing a similar turn of events in Iran. Iran, however, has moved steadily forward with a nuclear program ostensibly for peaceful uses amid growing international concern that Tehran will sooner or later deploy nuclear weapons. Extensive diplomatic efforts, spearheaded by the EU-3 ( France, Germany, and the UK) and backed by the United States, have failed to halt Iran’s nuclear quest. Iran has ignored UN Security Council resolutions and other attempts to influence Tehran to alter course. Even with the West’s fixation on preventing the emergence of an Iran with nuclear weapons, the policy community has not comprehensively assessed the consequences of an actual Iranian nuclear weapons capability for U.S. (and allied) security. This is an oversight the United States and its friends and allies can no longer afford to allow.

This project is based on the assumption, unpalatable as it may seem, that a nuclear Iran is all but inevitable, given the failure of Western policies, together with the apparent determination of Iran’s leadership to achieve nuclear-weapons status, notwithstanding Iranian assertions to the contrary. However opposed the United States may be to a nuclear Iran, it is essential to understand and anticipate as fully as possible what Iran as a state in possession of nuclear weapons, including warheads and delivery systems, would mean for the United States and its interests within the Middle East and at a broader level.

The project focuses on three crucially important questions: 1) How would an Iran with nuclear weapons affect U.S. interests in the Middle East, and what shifts in policy toward allies and others in the region would be necessary? 2) How would a nuclear Iran affect U.S. military requirements not only in the Middle East but at the broader international level as well? 3) What, in particular, would the United States need to do, diplomatically and militarily, to reassure friends and allies and to strengthen extended deterrence, in the face of a nuclear Iran?

All three questions are inextricably related to each other. The emergence of a nuclear Iran will change the geopolitical map of the region and beyond in ways that directly challenge vital U.S. interests, and how the United States chooses to restructure its military capabilities in response to a nuclear Iran will determine, in turn, Washington’s future ability to secure those same interests in the wake of likely geopolitical shifts. To a significant degree, moreover, America’s ability to secure those interests in the face of a nuclear Iran will rest on its ongoing capacity to reassure allies and sustain extended deterrence in credible, albeit quite new and innovative, ways. Understanding this three-fold dynamic more fully is essential if the United States is to manage the security challenges posed by the as yet unexplored consequences of an Iran with nuclear weapons.