Iran papers imply atomic subterfuge

Iranian documents obtained by the United Nations’ nuclear watchdog strongly suggest that Iran was working on a nuclear weapons design as recently as four years ago, U.N. officials disclosed last week in a private briefing.

The documents suggest that Iran’s research on nuclear weapons continued several months after U.S. intelligence officials say the effort was suspended, the International Atomic Energy Agency’s top nuclear security expert told diplomats in Vienna, according to notes taken by a participant.

Olli Heinonen, the IAEA’s deputy director general, was elaborating on a report released Feb. 22 that questioned whether Iran had come fully clean about its nuclear past.

In the report, the watchdog agency said that Tehran had not credibly explained documents that appeared to point to research programs devoted to uranium processing, high explosives and missile design -- all of which can be used in making nuclear weapons. Iran has denied ever seeking nuclear weapons and has dismissed the documents as fakes.

In the technical briefing Monday with diplomats from IAEA member states, Heinonen offered new details about the Iranian documents, according to notes obtained by the Washington Post.

Heinonen revealed that the IAEA had collected corroborating evidence, from the intelligence agencies of several countries, that pointed to sophisticated research into some key technologies needed to build and deliver a nuclear bomb.

Some of the documents, for example, described studies on modifying Iran’s Shahab missile to allow it to accommodate a large warhead, which would detonate about 600 yards above its target. The feature would make sense only if the warhead was nuclear, Heinonen suggested.

Iran’s U.N. ambassador, Mohammad Khazaee, told reporters Thursday that the new allegations are “baseless” and that Iran never sought to acquire nuclear weapons.

The U.N. Security Council is expected to vote Monday on a third resolution imposing travel and financial sanctions on Iranian individuals and institutions.

The measures are intended to pressure the Iranian government into suspending its enrichment of uranium and other nuclear programs with a potential military use.