It will mean the end of the possibility of the rise of a moderate form of Islam for the foreseeable future, perhaps generations. In the Arab/Muslim world, might is revered, and the victorious Islamists will therefore be revered. Moreover, they will have earned the right to claim that they constitute an unstoppable force. If America, the most powerful country in the world, surrenders to them because the Islamists murder fellow Muslims and killed the indescribably tragic but militarily small total of 3,000 soldiers in four years -- one-one-hundredth the losses the U.S. experienced in World War II -- who in the Muslim world will stand up to them?

Iraq will turn into a far more potent terror base than Afghanistan could ever be. One of the major powers of the Arab world, one of the most oil-rich countries in the world, may well be ruled by jihadists.

Moderate Arab regimes will likely be overthrown by a combination of an emboldened Iran and an Islamist Iraq that regards moderate Arabs and Muslims as loathsome as, if not more so than, Americans and Jews. It is almost inconceivable, for example, that the Jordanian monarchy would long survive an American defeat in Iraq.

The American military will suffer a crisis of morale that it will not soon overcome. Though defeated not by the Islamist enemy but by the American Left -- most particularly the Democratic Party and the mainstream news media -- it will be hard to convince many people to join or stay in the U.S. military. Why bother? Even if you do a great job, if you haven't done it all -- whatever 'all' means in a place like Iraq -- you will be told that you lost the war.

And those who have heretofore murdered fellow Muslims will focus their attention on murdering us. The left dismisses the argument that it is far better to fight them in Iraq than in Europe and America. But the dismissal is simply irrational. The people we are fighting, including Osama bin Laden and all the variations on al Qaeda, know that the battle for Iraq is the battle for their future -- that if they win in Iraq, they win all over the Middle East and beyond; that if they lose there, America and the West win.

But none of this matters to the Left because Democrats and others on the Left do not ask what will happen if America leaves Iraq. They are certain that the war was wrong, and that, in addition to handing George W. Bush and the Republicans a defeat, is what they seem to care about.