In a recent speech, Undersecretary of State John Bolton outlined Iran's furtive work to develop nuclear weapons and underscored the need for the international community to halt these efforts.

Today I'd like to speak about Iran, which has concealed a large-scale, covert nuclear weapons program for over eighteen years, and which, therefore, is one of our most fundamental proliferation challenges.

All of Iran's WMD efforts-chemical weapons, biological weapons, nuclear weapons, and ballistic missiles-pose grave threats to international security. Iran's pursuit of these deadly weapons, despite its signature on treaties that ban them, marks it as a rogue state, and it will remain so until it completely, verifiably and irreversibly dismantles its WMD-related programs.

There is much we do not know about Iran's weapons program, but much that we do know has been corroborated by a series of IAEA reports over the past year. It is the accumulation of this public and uncontradicted evidence, not just our own sensitive intelligence information, that leads us to our conclusions about Iran's true objectives. To this moment, Iran has never supplied coherent explanations for what it is up to ... yet another indication that we are watching a clandestine nuclear weapons program in operation.

Iran is pursuing two separate paths to nuclear weapons, one that would use highly enriched uranium for nuclear weapons and one that would use plutonium. Iran has tried to develop two different uranium-enrichment methods in order to produce weapons-grade uranium. First, it has established a number of facilities for the manufacture and testing of centrifuges (many of which are owned by military industrial organizations), a pilot enrichment facility designed for 1,000 centrifuges and a large buried facility intended to house up to 50,000 centrifuges. In parallel, Iran has pursued another program to enrich uranium with lasers.

Iran has also developed a program for the production of plutonium, an alternate path to nuclear weapons. Its purpose is to supply heavy water for a research reactor that Iran plans to begin constructing this year. The technical characteristics of this heavy water-moderated research reactor are optimal for the production of weapons-grade plutonium.

Another potential source of plutonium for weapons is the Bushehr light-water power reactor, which is currently under construction. That reactor is under IAEA safeguards. Russia has agreed to provide all fresh fuel for that reactor, and Iran and Russia are discussing an agreement to return all spent fuel to Russia. However, if Iran should withdraw from the Nonproliferation Treaty and renounce this agreement with Russia, the Bushehr reactor would produce enough plutonium each year for about 30 nuclear weapons.

The potential to produce plutonium is just one of several proliferation concerns with the Bushehr reactor. This large nuclear project provides Iran with access to nuclear technology as well as expertise and training in the construction and operation of nuclear facilities. Bushehr can be used as a cover and a pretext for other sensitive and troublesome nuclear fuel cycle activities.

The costly infrastructure to perform all of these activities goes well beyond any conceivable peaceful nuclear program. No comparable oil-rich nation has ever engaged, or would be engaged, in this set of activities-or would pursue them for nearly two decades behind a continuing cloud of secrecy and lies to IAEA inspectors and the international community- unless it was dead set on building nuclear weapons.

Cover stories put forward by Iran for the development of a nuclear fuel cycle and for individual facilities are simply not credible.

Consider also that the IAEA has discovered that Iran has produced Polonium 210 in the Tehran Research Reactor. The IAEA Director General's reports identify two primary uses for Polonium 210: neutron initiators in certain designs of nuclear weapons, and batteries for space satellites. Since Iran has no space satellites or deep space program, the nuclear weapons application is obviously of concern.

Another unmistakable indicator of Iran's intentions is the pattern of repeatedly lying to and providing false reports to the IAEA. For example, Iran denied testing centrifuges with uranium, denied the existence of a laser enrichment program, denied producing enriched uranium and denied receiving any foreign assistance in its centrifuge program. In each case, Iran confessed the truth only when confronted with irrefutable technical evidence from IAEA inspections. Iran's October 2003 submission to the IAEA, a declaration that was supposed to be the correct, complete and final story of Iran's nuclear program, omitted any mention of the development and testing of advanced P-2 centrifuges, which IAEA inspectors discovered in early 2004. If we permit Iran's deception to go on much longer, it will be too late. Iran will have nuclear weapons. We cannot let Iran, a leading sponsor of international terrorism, acquire nuclear weapons and the means to deliver them to Europe, most of central Asia and the Middle East, or beyond. Without serious, concerted, immediate intervention by the international community, Iran will be well on the road to doing so.