Olli Heinonen, Senior Fellow at the Belfer Center for Science and International Affairs, and Simon Henderson, Baker Fellow at the Washington Institute for Middle East Policy, write for the Washington Institute for Near East Policy that the final agreement with Iran over its nuclear program needs to take into account the efficiency of Iranian centrifuges when calculating breakout time, and not just the number of centrifuges allowed to enrich. They note that the exact efficiency in Separative Work Units (SWUs) of the Iranian IR-1 centrifuge is not exactly known, and therefore it is very possible that American estimates of Iran's enrichment capacity dangerously underestimates how much Iran is able to enrich, meaning that estimates putting its breakout time at one year are are inaccurate. They argue that it is necessary to understand exactly how efficient the Iranian centrifuges are in order to understand how many Iran needs to maintain a breakout time of about one year, and that this figure cannot only be calculated from the number of centrifuges Iran possess.

The final deal needs to specify the total enrichment capacity of Iran's installed centrifuges, mandate a robust verification regime, and include other restrictions to the nuclear program's size and content.

This report outlines the details of the Group of Governmental Experts’s deliberations, characterizes the range of expert views on aspects of a treaty — notably in relation to the dynamic correlation between a future treaty’s scope, definition, verification requirements and associated legal obligations and institutional arrangements — and presents the Group’s conclusions and recommendations.

Seven experts weigh in on the agreement's implications.

With reports that Washington and its partners may reach a nuclear accord with Iran in the coming days, a former senior IAEA safeguards official answers the most pressing questions about Tehran's program and how the agreement might affect its capabilities.

P5+1 negotiators are reportedly nearing an agreement with Iran that would dismantle some elements of Iran’s nuclear program while only providing limits on all other parts of the program. It also would maintain meaningful parameters that assure—at a minimum—a one-year breakout capability. The Iran Task Force has raised concerns about numerous aspects of the current trajectory of negotiations and the P5+1’s concessions to Iran throughout the negotiations. The following memo addresses one such area of concern, namely the “sunset” of enhanced verification requirements.

As negotiations between Iran and the great powers press forward, Secretary of State John F. Kerry seems to have settled on this defense of any agreement: The terms will leave Iran at least a year away from obtaining a nuclear bomb, thus giving the world plenty of time to react to infractions. The argument is meant to reassure, particularly when a sizable enrichment capacity and a sunset clause appear to have already been conceded. A careful assessment, however, reveals that a one-year breakout time may not be sufficient to detect and reverse Iranian violations.

This Policy Focus is intended to improve comprehension of the main issues and important technical details surrounding Iran's nuclear program. The core of the document explains the terms used by the International Atomic Energy Agency (IAEA), the world’s watchdog in ensuring that nuclear science and technology are used for peaceful purposes only.

In the preamble of the November 2013 Joint Plan of Action (JPOA), the P5+1 concurred that a comprehensive agreement would involve an Iranian domestic enrichment capability. This concession, immediately pocketed by Tehran, marked a fundamental change in the negotiations. Instead of a complete suspension of enrichment and reprocessing activities, as called for in multiple Security Council resolutions and a foundational plank of all previous negotiating positions, the P5+1 negotiators are now attempting to reach a comprehensive agreement with Iran that will establish a credible “threshold time window,” or “breakout time,” which would provide sufficient time to detect breakout and give the international community adequate time to respond to Iranian violations.

The following memo addresses one proposal mentioned in recent press reporting on the negotiations between the P5+1 and Iran. The result of such proposals recognizes Iran as a nuclear threshold state, which status the Task Force rejects.