I still believe there is no greater danger facing the world today than Islamic terrorism.

I also believe that — based on the information then available and the advice to the president by the CIA and its then director, George Tenet — our 2003 invasion and liberation of Iraq was justified.

Considering that even Saddam's own generals believed Saddam had WMD, it's easy to understand why the CIA came to an erroneous conclusion. However, if we had known then what we know now about the lack of WMD in Iraq — we should not have invaded.

Notwithstanding our mistake, we are nevertheless facing in Iraq the heart of the fundamental enemy of Western civilization and moderate Muslim states — Islamic terrorism. If the United States were supported by our allies with troops on the ground, which is the case in Afghanistan, we should stay in Iraq and endeavor to destroy the insurrectionists and terrorists and assist the Iraqi government to govern Iraq free from terrorism and jihadists.

Make no mistake. The terrorists and jihadists are seeking to turn Iraq into a radical Islamic state devoted to spreading terrorism, and providing sanctuary for those bent on destroying Western civilization. If they could, they would join with Iran to build what they hope would be an invincible army dominating first the Persian Gulf area starting at the Mediterranean Sea and encompassing all of central Asia. Their ultimate goal is to reestablish an Islamic Caliphate, stretching from Spain, across North Africa to the Middle East, central Asia, finally reaching Southeast Asia and Indonesia, an area that today has a population of 1 billion, 400 million Muslims, under one Islamic government and religious leader.

Not every Muslim is a terrorist, nor do all Muslims agree with this goal. But as journalist Abdel Rahman al-Rashed said, "It is a certain fact that not all Muslims are terrorists, but it is equally certain, and exceptionally painful, that almost all terrorists are Muslims."

If the United States, on its own, could defeat the terrorists and their goals by waging the battle now ongoing in Iraq, as President Bush believes we can, I would support that effort. But I, like most Americans, have concluded that we cannot do it alone. The casualties and cost are too great. I believe that unless we are joined by a significant number of our allies, regional and NATO, who would provide combat troops and share in the costs of war, we should leave Iraq.

In pursuit of such a decision, I urge the president to issue an ultimatum to our allies, both regional — Saudi Arabia, Turkey, Jordan, Kuwait, the Gulf States — and our 25 NATO allies, that unless a significant number reply affirmatively in 30 days to our ultimatum, we will begin immediately the process of withdrawal. At the same time, we should require the Iraqi government led by Prime Minister Nouri al-Maliki to call a special session of the Iraqi legislature to vote on a resolution stating their request of the U.S. and others to remain in Iraq, specifying the rules of engagement and the goals being sought by the Iraqi government and its allies. If the Iraqi government fails to do so within 30 days, then irrespective of the actions taken by our allies, we should leave. Americans and most of the people of the Western world appear not to know that the United Nations Security Council has approved the U.S. waging war in support of the Iraqi government. Indeed, King Abdullah of Saudi Arabia, supposedly our ally, recently referred to the U.S. presence in Iraq as "an illegal foreign occupation."

I have no doubt the war will continue for generations yet to come should we leave under any of these circumstances and that we will be compelled to fight that war in our homeland as the jihadists follow us across the seas to attack us here, as they already did in first attacking the World Trade Center on Feb. 26, 1993 and again on Sept. 11, 2001. There have been comparable attacks on Great Britain, Spain and other nations, including moderate Muslim countries, by the Islamic terrorists.

I believe there is a good chance that a significant number of our allies will respond affirmatively to our ultimatum, recognizing that they have more to lose than we do when the Iraqi refugees seeking relief from the ongoing civil war start to leave Iraq and stream across the borders of the neighboring states by the millions, bringing with them jihadists and terrorists and their suicide bombers. I recognize there is a greater likelihood that our allies will not respond affirmatively in significant numbers. That is particularly true with respect to the North Atlantic Treaty Organization (NATO), founded in 1949. Our allies in NATO have lost their will to stand and defend their values, as Great Britain found recently when it sought support from the members of the European Union for a United Nations resolution demanding that Iran immediately free the British marines taken hostage.

Great Britain found it had no support from its allies for clear, strong language. The Security Council issued instead a watered down statement simply expressing "grave concern" over Iran's actions. The will to live without fear no longer exists in Europe. The raison d'etre for NATO's existence — an attack upon one is an attack upon all — no longer governs that alliance. There is no surprise in that response, recognizing that the U.S. received the same response from NATO, excepting Great Britain and a few other small nations. Now, Great Britain will be leaving Iraq, as have most of our other allies, departing or reducing their forces.

For all practical purposes, NATO is dead. Its last achievement was stopping the Russian juggernaut and ultimately bringing down the Soviet Union. Europe, now believing it cannot prevent being overwhelmed by the Islamic tide, apparently prefers to accept it.

If on receiving the ultimatum, our allies recognize that they risk losing the future protection of their ally, the U.S., and its armed forces, which saved them from both German and Soviet occupation and protected them for so many years, they may have an epiphany.

No harm in trying. But there can be no bluffing on our part. Either they come in, or we get out.