At the G-20 summit in Pittsburg last September, President Barack Obama stood alongside the leaders of the United Kingdom and France and announced that Iran had built an underground nuclear facility at Qom. The disclosure was intended to signal international resolve and revive the impression that it was still possible to prevent Iran from acquiring nuclear weapons. Today, that naiveté persists, reinforced by misplaced confidence and wishful thinking.

Unfortunately for the optimists, whether or not Iran decides to join the nuclear club has for years been up to Iran. Since the revelation of Iran’s covert nuclear program in 2002, the United States has been unsuccessful in pursuing a “preventive approach” – that is, to deny Tehran access to a nuclear deterrent capability. This failure was inevitable, and primarily driven by a fundamental misperception within Washington’s foreign policy establishment: that with the invasion and occupation of Iran’s neighbors, the US had surrendered any strategic position to credibly coerce and deter Iran.

As witnessed repeatedly, whenever Tehran refused to alter its behavior in the face of international pressure, the solution was always to impose to “tougher” sanctions, with more participation from Russia and China. Yet this only highlighted the limitation of US coercive power, which suffers from an incoherent foreign policy. For example, the US seeks to force Iran to yield on its nuclear interests, and yet depends on Tehran for stabilizing Iraq and Afghanistan. This relationship favors the coerced, not the coercer.

Moreover, Washington has placed too much confidence in the efficacy of economic sanctions. Sanctions manipulate costs and benefits in order to compel the target to change its behavior. But historically they are unsuccessful. Coercive rather than preventive measures, sanctions do not remove the capacity to decide on the nuclear issue from Tehran’s hands. Iran has been impressive in limiting its isolation by exploiting its economic resources in the form of incentives to improve bilateral relations, usually with Western-cooperating states.

There are two scenarios that preclude Iran from gaining nuclear weapons: a coup by political forces that choose to relinquish the ambition, or regime-change through a full-scale military invasion. But both range from highly unlikely to unworkable. Recently, the most practical military option available, preventive air strikes on Iran’s nuclear infrastructure, has regained some momentum.

Such a policy is misguided. The consequences of a military operation would be enormous and success uncertain. But more importantly, a “successful” operation would not resolve the fundamental problem: stopping uranium enrichment. Rather, a preventive war would put the US in a worse position by legitimizing an eventual nuclear-armed Iran bolstered by domestic support, while also provoking an array of political, security, and economic aftershocks caused by the attack.

The reality is bleak. The US has no realistic preventive strategies to employ with Iran. However, regardless of the revisionism expressed by Iran’s conservatives, Iranian regional hegemony is not attainable. Tehran does not have the necessary infrastructure, economic prowess, or societal stability to project military power and domination over the Middle East. What will result from a nuclear capacity is a more confident Iran seeking greater influence and status and continuing to marginalize regional political forces aligned with the West.

At this late stage, the Obama administration must prepare the regional diplomatic groundwork for containing a nuclear Iran. Effective balance of power configurations do not form by design. They are created and reinforced by concerned states through constant cooperation and coordination in the military, political, and economic spheres. Although the US is wary of a military option, we should not assume that it has drafted an alternative containment strategy. As US Defense Secretary Robert Gates remarked in June: “I don’t think we’re prepared to even talk about containing a nuclear Iran … We do not accept the idea of Iran having nuclear weapons.”

Three crucial features must be included in any containment approach. First, the US must strive for a coherent foreign policy vis-à-vis the Islamic Republic, with interests pegged to regional stability, not democracy and regime-change. Secondly, the US should be prepared to play a pacifying role in the region: restricting Iran, but simultaneously working to minimize dangerous escalations involving local allies, particularly when it involves Israel.

Finally, the US must offer a degree of certainty to its allies in the region – building on, reiterating, and implementing promises of active engagement in containing Iran. The growing uncertainty about Washington’s commitment will dramatically increase the incentive for regional states to seek self-assurance, and hence, indigenous nuclear deterrents of their own. Egypt, Turkey, and Saudi Arabia are among those who might seek this form of reassurance.

Without the necessary diplomatic arrangements and American leadership, the danger is that a containment strategy may be both amorphous and fragile. Tehran could easily engage uncertain actors interested in hedging their bets and, consequently, erode the cohesiveness of the coalition aligned against it.

American prudence and recognition of the limitations of power should not be confused with weak and ineffective policymaking. Given the uncertainties involved when it comes to Iran, Washington should emphasize realpolitik in addressing Iranian nuclear ambitions.

Ramzy Mardini is a Middle East analyst at the Jamestown Foundation, a Washington-based foreign policy think tank. He previously served as a researcher on Iranian Studies at the Center for Strategic Studies at the University of Jordan. He wrote this commentary for THE DAILY STAR.