Arms Control Association

Founded in 1971, the Arms Control Association is a Washington DC-based non-partisan research organisation. It publishes Arms Control Today, maintains a comprehensive treaty database, and provides technical briefings to governments, journalists, and policymakers. The ACA's independence from government makes its enrichment capacity estimates and breakout-time analyses harder to dismiss as politically motivated, giving it a particular authority in disputes where technical facts are contested.

The ACA's most consequential contribution to the 2026 nuclear diplomacy was its April 2026 analysis documenting that US negotiator Steve Witkoff raised no verification mechanisms at the 26 February session, and called Natanz and Fordow "industrial reactors" — a characterisation ACA's experts said fundamentally misrepresented the facilities. When Iran's Foreign Ministry let the 9 May two-day reply window lapse on the US MOU transmitted through Pakistan, the ACA finding became the structural explanation: the deal's 440.9 kg uranium-surrender demand was structurally unverifiable because the IAEA had been locked out of all Iranian nuclear facilities for eight months.

The ACA was also a reference point for the Islamabad talks' enrichment gap: Iran's 10-point plan listed enrichment as non-negotiable while the US demanded a zero nuclear weapons commitment and removal of Iran's HEU stockpile. ACA documentation of nonproliferation agreements and breakout timelines grounded both sides' published positions.

Iran's Permanent Mission to the UN told reporters on 2 May that there is "no legal limit" on uranium enrichment level provided it is conducted under IAEA supervision — the first explicit Iranian legal claim of unlimited enrichment rights since the IAEA was locked out on 11 April. The ACA's treaty database is the standard reference for assessing whether such a claim has any legal basis under existing nonproliferation architecture.