I have just returned from my fourth trip to Iraq in the past 17 months and can report real progress there. More work needs to be done, of course, but the Iraqi people are in reach of a watershed transformation from the primitive, killing tyranny of Saddam Hussein to modern, self-governing, self-securing nationhood — unless the great American military that has given them and us this unexpected opportunity is prematurely withdrawn.

Progress is visible and practical. In the Kurdish north, there is continuing security and growing prosperity. The primarily Shiite south remains largely free of terrorism, receives much more electric power and other public services than it did under Saddam, and is experiencing greater economic activity. The Sunni triangle, geographically defined by Baghdad to the east, Tikrit to the north and Ramadi to the west, is where most of the terrorist attacks occur. And yet here, too, there is progress.

There are many more cars on the streets, satellite television dishes on the roofs, and literally millions more cell phones in Iraqi hands than before. All of that says the Iraqi economy is growing. And Sunni candidates are actively campaigning for seats in the National Assembly. People are working their way toward a functioning society and economy in the midst of a very brutal, inhumane, sustained terrorist war against the civilian population and the Iraqi and American military there to protect it.

It is a war between 27 million and 10,000; 27 million Iraqis who want to live lives of freedom, opportunity and prosperity and roughly 10,000 terrorists who are either Saddam revanchists, Iraqi Islamic extremists or al-Qaida foreign fighters who know their wretched causes will be set back if Iraq becomes free and modern. The terrorists are intent on stopping this by instigating a civil war to produce the chaos that will allow Iraq to replace Afghanistan as the base for their fanatical war-making.

We are fighting on the side of the 27 million because the outcome of this war is critically important to the security and freedom of America. If the terrorists win, they will be emboldened to strike us directly again and to further undermine the growing stability and progress in the Middle East, which has long been a major American national and economic security priority.

Before going to Iraq, I visited Israel and the Palestinian Authority. Israel has been the only genuine democracy in the region, but it is now getting some welcome company from the Iraqis and Palestinians who are in the midst of robust national legislative election campaigns; the Lebanese who have risen up in proud self-determination after the Hariri assassination to eject their Syrian occupiers (the Syrian- and Iranian-backed Hezbollah militias should be next); and the Kuwaitis, Egyptians and Saudis, who have taken steps to open up their governments more broadly to their people.

In my meeting with the thoughtful prime minister of Iraq, Ibrahim al-Jaafari declared with justifiable pride that his country now has the most open, democratic political system in the Arab world. He is right.

In the face of terrorist threats and escalating violence, 8 million Iraqis voted for their interim national government in January, almost 10 million participated in the referendum on their new constitution in October, and even more than that are expected to vote in the elections for a full-term government on Thursday. Most encouraging has been the behavior of the Sunni community, which, when disappointed by the proposed constitution, registered to vote and went to the polls instead of taking up arms and going to the streets.

I was thrilled to see a vigorous political campaign, and a large number of independent television stations and newspapers covering it.

None of these remarkable changes would have happened without the coalition forces led by the U.S. And, I am convinced, almost all of the progress in Iraq and throughout the Middle East will be lost if those forces are withdrawn faster than the Iraqi military is capable of securing the country.

The leaders of Iraq's duly elected government understand this, and they asked me for reassurance about America's commitment. The question is whether the American people and enough of their representatives in Congress from both parties understand this.

I am disappointed by Democrats who are more focused on how President Bush took America into the war in Iraq almost three years ago, and by Republicans who are more worried about whether the war will bring them down in next November's elections, than they are concerned about how we continue the progress in Iraq in the months and years ahead.

Here is an ironic finding I brought back from Iraq. While U.S. public opinion polls show serious declines in support for the war and increasing pessimism about how it will end, polls conducted by Iraqis for Iraqi universities show increasing optimism.

Two-thirds say they are better off than they were under Saddam, and a resounding 82 percent are confident their lives in Iraq will be better a year from now than they are today.

What a colossal mistake it would be for America's bipartisan political leadership to choose this moment in history to lose its will and, in the famous phrase, to seize defeat from the jaws of the coming victory.

The leaders of America's military and diplomatic forces in Iraq, Army Gen. George Casey and Ambassador Zal Khalilzad, have a clear and compelling vision of our mission there. It is to create the environment in which Iraqi democracy, security and prosperity can take hold and the Iraqis themselves can defend their political progress against those 10,000 terrorists who would take it from them.

Does America have a good plan for doing this, a strategy for victory in Iraq? Yes we do. And it is important to make it clear to the American people that the plan has not remained stubbornly still but has changed over the years.

Mistakes, some of them big, were made after Saddam was removed, and no one who supports the war should hesitate to admit that; but we have learned from those mistakes.

The administration's recent use of the banner "clear, hold and build" accurately describes the strategy as I saw it being implemented last week.

We are now embedding a core of coalition forces in every Iraqi fighting unit, which makes each unit more effective and acts as a multiplier of our forces. Progress in "clearing" and "holding" is being made. The Sixth Infantry Division of the Iraqi Security Forces now controls and polices more than one-third of Baghdad on its own. Coalition and Iraqi forces have together cleared the previously terrorist-controlled cities of Fallujah, Mosul and Tal Afar, and most of the border with Syria. Those areas are being "held" secure by the Iraqi military themselves. Iraqi and coalition forces are jointly carrying out a mission to clear Ramadi, now the most dangerous city in Al-Anbar province at the west end of the Sunni Triangle.

Nationwide, American military leaders estimate that about one-third of the approximately 100,000 members of the Iraqi military are able to "lead the fight" themselves with logistical support from the United States, and that number should double by next year.

If that happens, American military forces could begin a drawdown in numbers proportional to the increasing self-sufficiency of the Iraqi forces in 2006. If all goes well, I believe we can have a much smaller American military presence there by the end of 2006 or in 2007, but it is also likely that our presence will need to be significant in Iraq or nearby for years to come.

The economic reconstruction of Iraq has gone slower than it should have, and too much money has been wasted or stolen. Ambassador Khalilzad is now implementing reform that has worked in Afghanistan — Provincial Reconstruction Teams, composed of American economic and political experts, working in partnership in each of Iraq's 18 provinces with its elected leadership, civil service and the private sector.

That is the "build" part of the "clear, hold and build" strategy, and so is the work American and international teams are doing to professionalize national and provincial governmental agencies in Iraq.

These are new ideas that are working and changing the reality on the ground, which is undoubtedly why the Iraqi people are optimistic about their future — and why the American people should be, too.

I cannot say enough about the U.S. Army and Marines who are carrying most of the fight for us in Iraq. They are courageous, smart, effective, innovative, very honorable and very proud.

After a Thanksgiving meal with a great group of Marines at Camp Fallujah in western Iraq, I asked their commander whether the morale of his troops had been hurt by the growing public dissent in America over the war in Iraq. His answer was insightful, instructive and inspirational:

"I would guess that if the opposition and division at home go on a lot longer and get a lot deeper, it might have some effect, but, Senator, my Marines are motivated by their devotion to each other and the cause, not by political debates."

Thank you, general. That is a powerful, needed message for the rest of America and its political leadership at this critical moment in our nation's history.