But as laudable as the sentiments expressed in both addresses may be, unless his administration is definitively successful in stopping Iran from acquiring nuclear weapons, the result will be an administration faced with abandoning the policy hopes raised in one or both speeches. Certainly, the failure to stop the Islamic Republic from developing nuclear weapons is the most obvious obstacle to the president's nuclear disarmament vision. If Iran is able to acquire nuclear weapons, Egypt, Saudi Arabia and possibly even Turkey would be hard-pressed not to follow suit in an effort to maintain their presumptive positions of leadership within the Muslim world. And should those states head in that direction, there is no guarantee that a cascading proliferation effect would not take hold in other states in the Persian Gulf and Mediterranean basin. If the newfound interest of Egypt, the United Arab Emirates and Algeria in exercising their right to the 'peaceful' use of nuclear technology is any indication, we might already be headed down that road. Moreover, for many of these states, and most assuredly Egypt and Saudi Arabia, 'stopping' Iran means more than just reaching an agreement whereby the Iranian government forswears obtaining nuclear weapons. Success in this instance cannot leave Iran with a 'break-out option' -- in which civilian nuclear infrastructure and fuel could be used to produce bombs rapidly. Iran's neighbors are not going to feel secure if all that stands between them and a nuclear-armed Iran is a few months' time. At the moment, the administration's prospects for stopping and reversing Iran's nuclear program seem dim. If Las Vegas were laying odds, the betting line certainly would be in Iran's favor, with the oddsmakers having already seen this game played out with North Korea. Rather than marching toward a disarmed Iran and global nuclear zero, then, there are reasons to believe that the Obama administration instead will face the challenge of deterring and containing a nuclear-armed Islamic Republic, while simultaneously preventing the complete collapse of the nuclear nonproliferation regime. Each would require the United States to take an active role, bullying Iran's fearful neighbors not to pursue their own weapons and drawing them into an American security umbrella that itself would necessitate considerable interference in regional affairs. Already there are reports that the administration has begun to think about and plan for a containment strategy vis-a-vis Iran. But such a strategy comes with a cost. Given the aggressive character of the Iranian leadership and its willingness to use all the tools of statecraft at its disposal with neighbors and surrogates in the region, a simple, line-in-the-sand kind of containment probably would not be sufficient. To truly prevent Iran from using its new nuclear arsenal as a screen behind which it could safely assert its ideological and regional ambitions, the U.S. would have to increase its leadership role in the Middle East. The U.S. would be even more concerned with the policies of the states in the region. Would their leaders take our defense pledges seriously? Or would they instead attempt to play the U.S. off Iran, and vice versa? What kind of economic, military and intelligence assistance would each country need from Washington to help carry out the policy? And what demands would the U.S. public and members of Congress, in turn, make in exchange for that assistance? Whatever the merits of containment, the one thing that is almost certain is that the policy brings with it a need to exercise the kind of hectoring, quasi-hegemonic role that Washington once held over allies during the Cold War. And if containment does require a heavier U.S. hand, what then of Obama's vision for a new relationship with the Muslim world? In Cairo and at the United Nations, Obama laid out bold ambitions for the world and a new profile for American leadership. The road to realize those ambitions, however, runs directly through Tehran. Getting Iran right is, of course, important in its own right. But solving the Iranian nuclear issue is no less important to the president's larger vision. Schmitt is director of the program on advanced strategic studies at the American Enterprise Institute. 