American troops have now begun the first phase of withdrawing from Iraq and, under the US-Iraqi status of forces agreement, will be completely out by the end of 2011.

The Iraq War has been one giant roller coaster ride:

We executed a brilliant invasion and toppled their brutal dictator in a matter of days. (Cheers.)

Saddam Hussein was hunted down, tried and hanged. (Applause. )

Yet no sooner had President Bush declared, "mission accomplished" than the insurgency began. (Oops. )

Our occupation turned into a disaster of mismanagement, and large sections of the country succumbed to Sunni insurgents and Shiite militias. Al Qaeda gained a foothold and looked to make Iraq the base for operations throughout the Middle East. (Teeth gnashing, doom and gloom.)

In spite of calls for immediate withdrawal, President Bush doubled down with the surge,  replaced our military leaders, increased our troop strength and changed the rules of engagement. It was a huge gamble, but it led to one of the greatest turnarounds in recent military history. (New round of applause.)

As a result, we're now leaving Iraq with our heads held high, not with our tail between our legs. We're leaving behind an Iraqi government that, despite all its shortcomings, has a decent chance of success. We're turning security over to an Iraqi army that is multi-ethnic and finally able to stand on its own.

Enormous problems remain in Iraq, but they will be for Iraqis to solve. They still have to sort out who gets what of their oil wealth. They have to share power between Shiites, Sunnis and Kurds. They have to maintain order and prevent insurgencies from sprouting up and foreign fighters from entering. They have to hold their neighbors at bay. Only time will tell if the Iraqis succeed, but at least now they have a chance -- and a good one -- to become the first self-sustaining democracy in the heart of the Arab-Muslim world.

The war against radical Islam is far from over, but an essential battle has just been won. The roller coaster tide may not be finished for Iraq -- but the United States is getting off the train.

Kathleen Troia "KT "McFarland served in national security posts in the Nixon, Ford and Reagan Administration, and was a Deputy Assistant Secretary of Defense. Her Web site is KTMcFarland.com.