This essay begins with the assumption that Iran is intent on acquiring nuclear weapons and the long-range missile systems needed for their delivery. The assumption is based on documented evidence of Iranian efforts to acquire the elements essential for development of a nuclear program and on Iranian leaders' expressed interest in regional power projection based on weapons of mass destruction. This analysis does not attempt to determine whether Iran possesses nuclear weapons now or how long it might take to acquire them, both of which are important questions whose answers have significant consequences for the security of the United States. Instead, the authors focus on the approaches that policymakers have taken or could still take to avert or to slow this development, and they examine the potential impact on national interests, particularly on U.S. nonproliferation strategy, when Iran becomes a nuclear weapons state. They believe the issue that merits careful consideration has become how to manage a nuclear-armed Iran. This essay is meant principally as a policy analysis rather than an academic treatise. That is, it intends to build intellectual capital about how to manage the problem of a nuclear-armed Iran and to suggest courses of action that would minimize the negative impact on national interests.