Iraq is a long way from the U.S., but what happens there matters a great deal here. For the risks that the leaders of a rogue state will use nuclear, chemical or biological weapons against us or our allies is the greatest security threat we face.

We have no such weapons at all, no chemical weapons, no biological weapons.

When we're talking about technology that involves weapons of mass destruction, nuclear, chemical or biological weapons, there has to be an element of preemption.

The U.N. Security Council ordered Iraq in April 1991 to relinquish all capabilities to make biological, chemical and nuclear weapons as well as long-range missiles.

We need the UN, to deal with the threats to our common security from nuclear, chemical and biological weapons, not only in the case of Iraq. They must be tackled by the international community together, by strengthening conventions, treaties and agreements.

One letter to bin Laden reveals that al Qaeda was working on chemical and biological weapons in Iran.