On Thursday, the International Atomic Energy Agency issued its long-awaited report on Iran’s nuclear program to its 35 board members. The report states that Tehran is prohibiting inspections at sites that may be housing a nuclear weapons program. Moreover, the IAEA says the scope of Iranian cooperation is diminishing.

So is Iran building a bomb? The IAEA has no conclusive proof one way or another, and, it appears, neither does any other party outside the country. Yet we do not need to know the answer to that question. The report’s most important conclusion has been known by the international community long before the agency began its most recent investigations: the mullahs are continuing to enrich uranium. The report backs up Tehran’s claims that it is operating 3,000 centrifuges in Natanz. That number of machines, if working well, can produce enough weapons-grade material for a single nuclear weapon in a year’s time.

The spinning of centrifuges is by no means proof of bad intent. The machines can produce both lowly enriched uranium to generate electricity and highly enriched uranium for the cores of weapons. Which is it? In my view, that’s irrelevant because the United Nations has previously demanded that Iran halt enrichment and has imposed two sets of sanctions for its failure to stop.

Nuclear weapons are so inherently dangerous that merely violating the mandates of the United Nations with regard to them should, by itself, be considered grounds for the use of force. The Bush administration should not have tried to make the case that Iraq was in possession of weapons of mass destruction. It should have premised its decision to go to war on the inarguable failure of Saddam Hussein to comply with the U.N.’s weapons inspection regime. On Tuesday, Ronald Kessler released a book, The Terrorist Watch, which reveals that the Iraqi dictator was bluffing about his possession of weapons of mass destruction in order to forestall an attack from Iran. In order to maintain the appearance of the possession of an arsenal, he made a mockery of UN inspections. So in the process he undermined the security of the international community by weakening its first line of defense against the spread of the world’s most destructive weaponry.

There is no point in maintaining an organization designed to provide collective security if it cannot enforce its mandates. The UN failed with regard to Iraq and left the matter to the United States and the other members of the Coalition in 2003. The world body has one more chance to prove that it still has a role in the world. And on Thursday, the IAEA put the issue squarely before the Security Council.