One year ago, I came to the International University to report on international efforts to convince Iran's leaders to give up their pursuit of nuclear weapons.

The IAEA Board had just reported Iran's violations of Agency safeguards to the UN Security Council and required Iran's leaders to suspend activities of international concern.

I can report good news and bad news since my remarks last year.

The Bad News: Iran's Defiant Nuclear Pursuits

The bad news is that leaders continue in their failure to cooperate with the IAEA and to abide by their international commitments.

The UN Security Council has now required Iran to cooperate with the IAEA in answering troubling questions about their activities.

But, as detailed by IAEA Director General Mohammed ElBaradei on February 22 in his latest report, Iran's leaders still refuse full cooperation.

Instead of welcoming IAEA inspectors, Iran has arbitrarily denied some 50 inspectors access into the country.

Instead of letting IAEA inspectors visit all facilities of interest, Iran has limited their access by refusing to implement the Additional Protocol, an instrument that grants the Agency added information and authority to do its job.

Instead of answering troubling questions about ties to the A. Q. Kahn network, an illicit trafficking network in nuclear weapons technology, Iran still refuses to turn over a document it received from the network on machining uranium into a hemisphere, a necessary step in fabricating the core of a nuclear weapon.

Because Iran has refused to provide maximum cooperation and transparency, the Director General concluded that the Agency cannot "provide assurances about the absence of undeclared nuclear material and activities in Iran or about the exclusively peaceful nature of that programme."

This is troublesome.

Over three years after Iran's secret nuclear program was uncovered, Iran's leaders still refuse to take simple steps to show the world its program is peaceful.

Since the Director General's report on February 22, Iran's leaders have reduced cooperation even further.

Last week Iran's authorities told the IAEA that they will no longer provide timely information on new nuclear facilities.

This is contrary to previous Board decisions and contrary to the practice of other countries with nuclear activities under IAEA safeguards.

It can only cast further doubt on the nature of Iran's activities and the intentions of its leadership.

On February 22, the Director General also reported that Iran's leaders are failing to comply with UN Security Council requirements to suspend activities related to uranium enrichment and plutonium production.

The report documents that Iran's activities related to uranium enrichment have been expanded.

It also documents that work continues on a heavy water reactor, a type of reactor well configured to produce plutonium.

These activities are not necessary for peaceful purposes.

But plutonium and highly-enriched uranium are the two special nuclear materials that can be manufactured into the core of a nuclear bomb.

Iran's work on uranium enrichment seems most advanced.

The Director General reports that Iran is moving ahead with installation of centrifuges, used to enrich uranium, at the large underground hall at Natanz.

He further reports that Iran intends to have 3,000 centrifuges operating in the near future.

According to estimates from the International Institute for International Studies, 3,000 centrifuges operating smoothly could produce enough highly enriched uranium for one nuclear weapon in less than a year.

The Director General also reports that Iran has moved 8.7 tons of uranium hexafluoride, the feedstock for enrichment, into the Natanz enrichment complex. According to IISS estimates, this is adequate UF6 to produce highly enriched uranium for one weapon.

And 8.7 tons is a drop in the bucket: The Director General reports that, as of January, Iran had processed enough uranium at the Esfahan conversion facility to produce over 250 tons of UF6.

This does not mean that Iran can produce a nuclear weapon by the end of this year.

We think it will take Iran longer than that.

But the bad news is that Iran's leaders are moving forward, step by defiant step, to produce material that can be used in nuclear weapons.

The Good News: The International Response

So what is the good news?

The good news is that Iran's defiance has slowly but surely united the world in a common diplomatic approach to convince Iran's leaders to change course.

The Director General's report on February 22 was followed a month later by the UN Security Council adopting Resolution 1747.

This is the third resolution that the Security Council has adopted on Iran's nuclear activities and the second imposing targeted sanctions.

Like the last, the resolution was adopted unanimously.

Not only did Russia and China and all other Permanent Members of the Security Council vote "yes." But countries like South Africa - a leading member of the Non-Aligned Movement, Qatar - the Council's Arab member, and Indonesia - a large Muslim state, joined in adopting the resolution and expressing their concern.

So did Belgium, Italy, and Slovakia; Congo and Ghana; Panama and Peru.

Iran's leaders are digging their country into an ever deeper hole of violations.

They have subjected Iran to three UN Security Council resolutions.

They have placed Iran among the small number of countries under Chapter VII sanctions.

They have united the world against their nuclear ambitions.

Our goal is one shared with Europe, Russia, China, and countries around the world: To convince Iran's leaders to comply with Security Council requirements.

If Iran's leaders suspend activities of international concern, the Security Council will suspend international sanctions.

This will open the way for negotiations, including with the United States.

It will open the way for Iran to take advantage of the generous package offered last June by six Foreign Ministers of Europe, Russia, China, and the United States.

This package contains important benefits, including access to state-of-the-art technology for power reactors and legally-binding assurances of nuclear fuel supply.

Convincing Iran's Leaders to Change Course

Our goal is a diplomatic solution, but this is a tough diplomatic challenge.

Iran's leaders have shown little inclination to abide by international commitments or to respond to international concerns.

To succeed diplomatically, countries across the world must work together and use a full range of non-military instruments - from global diplomacy to international sanctions - to convince Iran's leaders to shift from their current course of confrontation and noncompliance to one of cooperation and negotiation.

That would be best for global security.

That would be best for the region.

And it would be best for the people of Iran.