Our last, best hope in Iraq -- Gen. David Petraeus -- reminded Pentagon reporters this week of a critically important fact long forgotten by most observers: Our real enemy in Iraq, the true source of all the murders, mayhem, and instability, is not sectarian strife. And it's not the Sunnis or the Shiites, either. The real enemy we face in Iraq is al-Qaida.

According to the top American commander in Iraq, al-Qaida's No. 1 priority is defeating the United States in Iraq. The general called this organization "public enemy No. 1," adding that "Iraq is, in fact, the central front of al-Qaida's global campaign."

Senate Majority Leader Harry Reid doesn't understand this. Nor, for that matter, do the other defeatist Democrats carelessly demanding our immediate withdrawal. They fail to grasp that the root of our problems in Iraq -- again, the true source of the hostilities -- remains al-Qaida. These murderous thugs are fomenting the sectarian strife on both sides of the Iraqi street. Their tactic is the nadir of nihilism.

In contrast to the blind Harry Reid contingent, I'd like to highlight one remarkably clear thinker who does get what's going on in this war -- someone who recognizes the true enemy and is able to articulate his position in breathtaking clarity. I'm talking about Sen. Joe Lieberman of Connecticut. Frankly, no public official understands what's at play better than Lieberman. He set forth his lucid position in Thursday's Washington Post and brought it alive when I interviewed him on "Kudlow & Company" later that day.

Lieberman forcefully stated that "al-Qaida, after all, isn't carrying out mass murder against civilians in the streets of Baghdad because it wants a more equitable distribution of oil revenue. Its aim in Iraq isn't to get a seat at the political table; it wants to blow up the table -- along with everyone seated at it."

To miss this point is to miss the crux of this conflict. There can be no doubt about the central role being played by al-Qaida in this war. Its domination of the Iraqi theatre is unmistakable. It is the hinge of this war. And, lest we forget, these are the same murderers who bombed us on Sept. 11, 2001. They are terrorists who have made crystal clear their intention to subvert us at every turn. And make no mistake about it -- they are regrouping in order to strike us again.

This is why the stakes are so high and why we must not interrupt the surge. This is why there can never be a so-called "political settlement" unless and until the United States can militarily cripple al-Qaida in Iraq. Only then can a political settlement be reached, one that can provide for a healthy representative government, oil sharing, proportional staffing in ministries and on down the line.

Without question, it is a near certainty that Iran and Syria are helping al-Qaida with money, arms and explosives. And, yes, if we leave now, al-Qaida will have an open field in which to expand its operations and prepare for the ultimate attack on the United States. In fact, the Defense Department and the CIA just nabbed a high-ranking al-Qaida operative known as al-Iraqi. He was a key link between the Taliban in Afghanistan, al-Qaida in Iraq and al-Qaida members in Iran. And while it's great news we got him, he's one more reminder that this network is strong and playing for keeps. Continued...