The bad news is that the International Atomic Energy Agency (IAEA) has concluded that Iran operated a secret nuclear program and formally breached its obligations under the Nuclear Nonproliferation Treaty (NPT). The good news is that the agency caught the clandestine program and forced Tehran to admit its behavior and accept an additional protocol allowing enhanced nuclear inspections. This happy outcome is proof of the importance of the NPT regime and the IAEA, and the need for continuing vigilance to enforce its provisions. Nuclear proliferation can be stopped, but the nonproliferation regime requires constant care and attention.

Iran has, under the terms of the NPT, operated a nuclear energy program. Despite repeated allegations that the country had a secret nuclear weapons program, Tehran maintained that its program was consistent with its NPT obligations, oriented toward the production of nuclear power. It vehemently denied charges of cheating.

Those protests began to ring hollow earlier this year when Tehran was forced to admit the existence of a secret nuclear facility. It then conceded that it had enriched uranium, a key step in weapons production. Faced with growing international concern and the possibility of isolation, the Iranian government last month provided a more complete history of its nuclear energy program to the IAEA. The new history is an eye-opener and put the lie to Tehran's previous denials.