Facts on the ground also compel us to recognize that Iran is doing everything in its power to drive us out of Iraq, including providing substantive support, training and sophisticated explosive devices to insurgents who are murdering American soldiers. Iran has initiated a deadly military confrontation with us, from bases in Iran, which we ignore at our peril, and at the peril of our allies throughout the Middle East.

Lieberman can claim this, but the military and intelligence agencies continue to hedge on the topic of Iranian sponsorship of the insurgency. On the other hand, our military and intelligence agencies are quite actively working with the Saudis to fund Sunni militias in Lebanon while turning a blind eye to the Saudis doing the same in Iraq.

But, never mind Lieberman's assertions of what constitutes reality on the ground. We know his agenda is to maintain public support for the war. What is more interesting is the question of what Lieberman is afraid of. Why does he cling so doggedly to this war? He offers some clues.

The precipitous withdrawal of U.S. forces would not only throw open large parts of Iraq to domination by the radical regime in Tehran, it would also send an unmistakable message to the entire Middle East--from Lebanon to Gaza to the Persian Gulf where Iranian agents are threatening our allies--that Iran is ascendant there, and America is in retreat. One Arab leader told me during my trip that he is extremely concerned about Tehran's nuclear ambitions, but that he doubted America's staying power in the region and our political will to protect his country from Iranian retaliation over the long term. Abandoning Iraq now would substantiate precisely these gathering fears across the Middle East that the U.S. is becoming an unreliable ally.

That is why--as terrible as the continuing human cost of fighting this war in Iraq is--the human cost of losing it would be even greater.

These are real concerns even if some of the rhetoric is a little overblown. Now, I have a long-term vision of America playing a less central and hegemonic role in the Middle East. But, in the short-term there is one area where I have sympathy for Lieberman's position. I'll spell it out because it leads me to a conclusion diametrically opposed to Lieberman.

When Lieberman talks about America's will and staying power he is really talking about a change in the American public's consciousness. In other words, in a kind of domino-effect, a withdrawal from Iraq might snowball into a larger withdrawal from the whole region. And, while I have no problem with that in the long-term, it could create needless problems, like energy disruptions that could cause financial ruin to the world markets. The fiasco in Iraq could lead to domestic political pressure to draw down our presence in the Middle East, and that pressure might not be intelligently calibrated to avoid really big, and avoidable, problems.

And we could begin to feel those problems faster than expected if our allies get the sense that America lacks the 'political will to protect [them] from Iranian retaliation over the long term'. Weak nations, like Kuwait, the Emirates, and even Saudi Arabia, will appease those most likely to threaten them if they don't have a protector to appease. That's why any transition out of the Persian Gulf, for example, would require careful planning and diplomacy. Beyond that consideration, the time is not yet ripe for America to abandon its central role in the Gulf region. A real roll-back of our forward-leaning basing strategy there needs to be accompanied by a major effort at energy independence. We can only truly ignore the region when we don't have to worry about the economic consequences of energy disruptions, boycotts, or takeovers by rival powers (such as China, or a resurgent Russia, or even Iran).

In other words, we do not want to retreat from the region precipitously...pushed by domestic political disgust with the cost and incompetence of U.S. foreign policy. Therefore, some measure of U.S. will and resolve must be maintained for a broader presence in the region. And this is where I disagree with Lieberman.

The continuation of the Iraq War is the biggest threat to that American will and resolve. If you are looking for a reason, look no further than the staggering cost in dollars. The price tag for Iraq is simply not sustainable. If you want another reason, look at the damage it is doing to our armed forces...especially their readiness, but also equipment and recruitment. There has to be a cost/benefit analysis. For Lieberman, the benefit is wholly speculative...things could get much worse. And they could and probably will. But we cannot avoid the fact that our current strategy is not sustainable. We HAVE to change it. And the sooner we do it the more support we will retain for a containment strategy.

What is a reasonable containment strategy? At the most general level, it means containing the violence in Iraq to within the borders of Iraq. That is what Murtha is getting at when he says that we will maintain a force 'over the horizon'. That force will be there to assure the Iranians and the Turks don't get any ideas about invading with ground troops and/or making any territorial claims.

That is not to say that America can have no ongoing role in minimizing the violence within Iraq, but that must be done in concert with the international community.

Lieberman concludes today's essay with the following:

I returned from Iraq grateful for the progress I saw and painfully aware of the difficult problems that remain ahead. But I also returned with a renewed understanding of how important it is that we not abandon Iraq to al Qaeda and Iran, so long as victory there is still possible.

And I conclude from my visit that victory is still possible in Iraq--thanks to the Iraqi majority that desperately wants a better life, and because of the courage, compassion and competence of the extraordinary soldiers and statesmen who are carrying the fight there, starting with Gen. Petraeus and Ambassador Crocker. The question now is, will we politicians in Washington rise to match their leadership, sacrifices and understanding of what is on the line for us in Iraq--or will we betray them, and along with them, America's future security?

On the subject of al-Qaeda, the Iraqis are most likely to eradicate them once they have no common enemy. Iraq has been radicalized by four years of war but they remain a largely secular society. If we want to root out al-Qaeda in Iraq we should leave the job to the Iraqis. On the larger question of Iranian influence and nuclear ambitions, we will have to decide how best to combat that. But we aren't going to succeed by bankrupting ourselves, breaking our armed forces, and continuing to alienate the international community. That will lead to a cratering of domestic support for any hegemonic role in the region at all.

And, as I have said throughout this essay, while I have a long-term goal of winding down our hegemonic role in the region, I want to see that done in a thoughtful, patient, and responsible manner...and not as a kneejerk capitulation to domestic fury at Bush's terrible leadership.

Staying in Iraq is the worst thing we can do if we want to keep some stability in the region.