In a region of troubles, the negotiations over Iran’s nuclear program stand out. The first-step agreement, signed in November 2013, broke a decade of futile diplomatic forays punctuated by mutual escalation. The product of a rare confluence of political calendars and actors, it set a framework for a balanced arms-control agreement that could form the basis of a comprehensive nuclear accord. But reasons for caution abound. It is easier to pause than to reverse the escalation pitting centrifuges against sanctions. Mistrust remains deep, time is short, and the process remains vulnerable to pressure from domestic and regional detractors. In bringing the sides together, the accord revealed the chasm that separates them. Success is possible only with political will to isolate the deal – at least for now – from its complex regional context. It will ultimately be sustainable only if the parties, building on its momentum, recognise that their rival’s legitimate interests need to be respected. But a far-reaching resolution of differences will be possible only after a relatively narrow, technical nuclear agreement.

The main objective of the P5+1 (the five permanent UN Security Council members plus Germany) is to constrain Iran’s nuclear program. In Geneva, where the agreement – officially known as the Joint Plan of Action – was signed, the group for the first time agreed to Iran maintaining some enrichment capacity. But it has demanded that Tehran significantly roll back its enrichment capabilities, close the bunkered enrichment facility in Fordow and heavy-water plant in Arak; and demonstrate the peaceful nature of its nuclear program by detailing past activities and allowing, for an extended period, intrusive monitoring. Fearing that it would be easier for Iran to reverse its nuclear concessions than for the West to renew its isolation, the group insists on retaining sanctions leverage, even through implementation of the final step of a comprehensive agreement.

Iran believes that the P5+1’s objective is to contain not simply its nuclear program, but also the Islamic Republic itself. It contends that it has been singled out, uniquely among signatories of the 1968 Treaty on the Non-Proliferation of Nuclear Weapons (NPT), to prove a negative, that its nuclear program does not aim at weaponisation. Tehran insists on preserving a substantial part of its nuclear infrastructure, in view of the enormous cost it has paid for it. While willing to accept heightened verification measures in order to enable the International Atomic Energy Agency (IAEA) to establish the peaceful nature of its program, it insists that they be temporary and respectful of its national security requirements. It also demands significant and immediate Western reciprocation of any nuclear concession.

From these starting points, it would appear that the P5+1’s maximum – in terms of both what it considers a tolerable residual Iranian nuclear capability and the sanctions relief it is willing to provide – falls short of Iran’s minimum. Nevertheless, it is still possible to reach a comprehensive agreement on a limited nuclear program – though an uncomfortable one for sceptics like Saudi Arabia and Israel that object on principle to Iran retaining any enrichment capacity. Negotiators will not get far, however, by trying to define Iran’s “practical needs” for enriched uranium (an approach endorsed in Geneva), since needs are a matter of interpretation about which Iran and the P5+1 differ. Focusing on “breakout time” – the time required to enrich enough uranium for one weapon – will not stand them in better stead, as it is based on theoretical, unpredictable and plastic calculations.

What is needed, rather, is a compromise that satisfies both sides’ irreducible, bottom-line requirements: for Iran a meaningful enrichment program, continued scientific advancement and tangible sanctions relief; and for the P5+1, a firewall between Iran’s civilian and potential military nuclear capabilities, airtight monitoring mechanisms and sufficient time and Iranian cooperation to establish trust in the exclusively peaceful nature of the country’s nuclear program. Such a solution would enable them to sell the deal at home and serve as a springboard for developing a different kind of relationship.

This report presents a blueprint for achieving that agreement. It is guided by four objectives: building a firewall between Iran’s civilian and potential military nuclear capabilities by constraining the most proliferation-prone aspects of its nuclear program; enhancing transparency by establishing rigorous monitoring and verification mechanisms; ensuring implementation and deterring non-compliance by establishing objective and compulsory monitoring and arbitration mechanisms, as well as by devising, in advance, potential responses to breaches by either party; and bolstering the parties’ incentives to remain faithful to the agreement by introducing positive inducements rather than purely negative ones.

A comprehensive agreement based on these principles should be implemented in three phases, the first of which would start with steps that clearly demonstrate the parties’ commitment to the process and provide them with immediate tangible benefits, while delaying the heavy lifting until their investment in the process is greater, the costs for withdrawing higher and at least some sceptics have bought into the process.

The basic elements of the approach include:

• permitting Iran a contingency enrichment program that could be dialled up in the event of nuclear fuel denial, though constrained enough that any breakout could be promptly detected and, through a defined response, thwarted;
   
• converting the heavy-water research reactor in Arak to diminish the amount of plutonium it produces;
   
• transforming the bunkered facility in Fordow into a proliferation-resistant research and development centre;
   
• introducing transparency measures that exceed Iran’s existing obligations but conform with its legitimate security and dignity concerns and that the P5+1 should acknowledge will be temporary;
   
• providing Iran significant but reversible sanctions relief in the early stages of the comprehensive agreement, followed by escalating further relaxation, including open-ended suspension or termination of restrictions in accordance with progress on the nuclear front;
   
• establishing positive incentives by strengthening trade ties, and increasing civilian nuclear and renewable energy cooperation between the parties; and
   
• coordinating messages to reassure both sides’ regional allies and rivals, and to avoid inciting hardliners as leaders sell the agreement at home.

The detailed recommendations that follow lay out this path in 40 actions. It is a path that carries risks for both sides. There is no guarantee that Iran will remain faithful to its commitments after international attention shifts. Nor is there certainty that the U.S. Congress will accept the deal and provide the president with the necessary authority on sanctions.

These risks notwithstanding, the alternatives are less attractive. A series of partial, interim deals would lessen the chances of reaching a final agreement, fall short of satisfying either party and strengthen hardline critics. A return to the status quo ante, with each side ratcheting up its leverage in the hope of forcing the other to capitulate, would very possibly lay the tracks for a scenario in which Iran attains a nuclear bomb while sanctions cause it grave harm. Most dangerous would be a military strike, which could set back Iran’s nuclear march temporarily, but at the cost of spurring it to rush toward the ultimate deterrent, while retaliating in a variety of asymmetric or non-conventional ways, with unpredictable but certainly tragic regional ramifications.

If odds of the talks collapsing are high, the stakes of failure are higher. At the very least, a breakdown would reduce the possibility of success later, as it would erode trust and stiffen positions. The region and the world will be a safer place for a compromise that protects everyone’s core interests, contains Iran’s nuclear program and rehabilitates the country’s economy and international standing.