Despite what could be good intentions, Iran may not be technically capable of safeguarding its nuclear arsenal and keeping it under centralized command and control. Assessing the Iranian regime’s ability to secure its nuclear weapons is a trying exercise, due to its notoriously opaque nature and the lack of good intelligence on the country’s national-security apparatus. Moreover, some rogue elements within the Islamic Revolutionary Guard Corps or the political elite could be tempted to supply nuclear technology to friends and allies, a remote possibility given the huge risks and high costs. Irrespective of what Iran says and does, all these objective risks may be viewed by the United States as too high—and ample reason to opt for a preventive strike.

Washington will theoretically have two distinct options should Iran go nuclear: prevention or containment and deterrence. But in reality there will be a strong connection between the two. Indeed, the feasibility of one will depend on the other. For containment to succeed, the United States would need a credible deterrent in the eyes of Iran. A credible deterrent, on the other hand, will require a real first-strike preventive option. In other words, prevention will complement containment. Whether the United States will be able to develop viable preventive and containment options is hard to predict. But preparation for a nuclear Iran should start today, not tomorrow.

Bilal Y. Saab is a Visiting Fellow at the James Martin Center for Nonproliferation Studies at the Monterey Institute of International Studies.