Atlantic Council

War with Iran is not inevitable, but U.S. national security would be seriously threatened by a nuclear-armed Iran. Particularly given the recent speeches at the U.N. General Assembly, military action is being discussed intensely. Public discussion of military action, however, is often reduced to rhetoric and partisan politics. We propose a nonpartisan, reasoned debate about the implications for the United States of another war in the wider Middle East.

Thomas Jefferson said, “In a republican nation whose citizens are to be led by reason and persuasion, and not by force, the art of reasoning becomes of first importance.” In a publication released this month, “Weighing Benefits and Cost of Military Action Against Iran,” and posted online at TheIranProject.org, more than 30 former senior U.S. government officials and regional experts have come together to invoke the art of reasoning. We do not agree with every word in the report, but we have shared understandings of its message.

We joined this effort because we believe a fact-based discussion of the objectives, costs, benefits, timing, capabilities and exit strategy should govern any decision to use military force. Our position is fully consistent with the policy of presidents for more than a decade of keeping all options on the table, including the use of military force, thereby increasing pressure on Iran while working toward a political solution. Since the consequences of a military attack are so significant for U.S. interests, we seek to ensure that the spectrum of objectives, as well as potential consequences, is understood.

If the United States attacks, it could set back for several years Iran’s ability to build a nuclear weapon. If the objective were large-scale damage to Iran’s military and weapons capability, the United States could achieve substantial success. But without large numbers of troops on the ground, we doubt that U.S. military attacks from the air — even if supplemented by other means such as drones, covert operations and cyberattacks — could eliminate Iran’s capability to build a nuclear weapon, unseat the regime or force it to capitulate to U.S. demands.

U.S. intelligence officials have said they believe Iran already has the know-how and much of the technology to build a nuclear weapon. U.S. and Israeli intelligence officials agree that Iran’s leaders have not yet made a decision to build one. But the U.S. government has indicated that if Iran were to produce weapons-grade enriched uranium and build a weapon, the military option must be considered. Defense Secretary Leon Panetta said this month that the United States would have “a little more than a year . . . to take the action necessary” should Iran decide to make a dash for a nuclear weapon. We believe that there would be sufficient warning time to decide how to respond.

Though not the only way to achieve these objectives, a U.S. attack would demonstrate the country’s credibility as an ally to other nations in the region and would derail Iran’s nuclear ambitions for several years, providing space for other, potentially longer-term solutions. An attack would also make clear the United States’ full commitment to nonproliferation as other nations contemplate moves in that direction.

The costs are more difficult to estimate than the benefits because of uncertainty about the scale and type of Iran’s reaction. Iran is likely to retaliate directly but also to pursue an asymmetrical response, including heightened terrorist activity and covert operations as well as using surrogates such as Hezbollah. An increase in the price of oil could keep the market unstable for weeks or months and disrupt the global economy.

The conflict could also escalate into a regional war involving Syria, Hezbollah, the Palestinians and other Arab states and terrorist groups. While a U.S.-led attack on Iran might be quietly welcomed by the leaders of many Arab states, and certainly by Israel, it would most likely be greeted with hostility from wide swaths of the region’s Muslims.

Other consequences might include the increased likelihood of a decision by Iran to build a nuclear weapon; more instability in a region still seeking its footing; and the opportunity for extremist groups such as al-Qaeda to attract recruits.

When he accepted the Nobel Peace Prize, President Obama wisely described the dilemma that the United States faces as a great nation: “part of our challenge is reconciling these two seemingly irreconcilable truths — that war is sometimes necessary, and war at some level is an expression of human folly.” The United States needs to have a nonpartisan, reasoned discussion about the choice between necessity and human folly.

Retired Adm. William J. Fallon was head of U.S. Central Command from 2007 to 2008. Chuck Hagel, chairman of the Atlantic Council, was a U.S. senator from Nebraska from 1997 to 2009. Former Indiana congressman Lee Hamilton was vice chairman of the 9/11 Commission. Thomas Pickering, an Atlantic Council Board member, was undersecretary of state for political affairs from 1997 to 2000 and previously served as U.S. ambassador to Russia, Israel, Jordan and the United Nations. Retired Gen. Anthony Zinni was head of U.S. Central Command from 1997 to 2000. This piece was originally published in The Washington Post.