Iraq Withdrawal Signals New Phase, But War is Not Over

The withdrawal of the last U.S. combat brigade from Iraq marked a major milestone in the seven year, five month conflict and has been hailed as a sign the U.S.-led war could soon be over.

But hours after the 440 members of the 4th Stryker Brigade, 2nd Infantry Division rolled across the Kuwaiti border, unfurled American flags and lit cigars in celebration of their success, military officials cautioned that the war -- and the potential for combat -- in Iraq is not yet finished.

VIDEO: Soldiers cheered as they crossed the border out of Iraq.Play
Combat Brigades Leave Iraqi War Zone to Head home

"The combat mission is still under way," Pentagon spokesman Geoff Morell told MSNBC. "It will not formally change until the end of the month."

The U.S. still has around 52,000 troops in Iraq after Wednesday's withdrawal, but that will be trimmed to 50,000 noncombat troops by the end of this month. They will work largely behind the scenes, training, advising and assisting their Iraqi peers but won't be entirely free from danger – or combat.

"I don't think anybody should be under illusions our forces will not be armed. They will be armed," Morell said. "They very well could be in combat situations even after the end of the month."

The words are a striking juxtaposition with the scene playing out along the Iraq-Kuwait border and headlines in major newspapers across the U.S. They also serve as a reminder of the previous signs and signals of a possible end to the violent conflict in Iraq that now ring hollow.

U.S. invasion of Iraq

When the war began in March 2003, U.S. officials touted a "shock and awe" campaign that would deal a quick, one-two punch to Saddam Hussein's regime and any his supporters.

Less than two months later, President George W. Bush landed in a fighter jet on the USS Abraham Lincoln and famously heralded victory.

President Bush on USS Abraham Lincoln

"Major combat operations in Iraq have ended. In the battle of Iraq, the United States and our allies have prevailed," he said under a banner that read "Mission Accomplished."

Then, as war raged on, Bush reminded Americans in December 2003, that the capture of Saddam Hussein -- itself a major milestone -- likely would not bring the conflict to an end.

"The capture of Saddam Hussein does not mean the end of violence in Iraq. We still face terrorists who would rather go on killing the innocent than accept the rise of liberty in the heart of the Middle East," he said.

Capture of Saddam Hussein

By 2005, Iraq held its first national elections in a post-Saddam era and the government began drafting a new constitution. It offered a glimmer of hope for an independent Iraq and an end to U.S. military engagement.

But the sectarian violence did not abate, and it threatened to engulf Iraq. Then, Bush announced an escalation of troops known as the "surge."

Seven Years in Iraq From Shock and Awe to Today

"This is not the fight we entered in Iraq, but it is the fight we are in," he said in his State of the Union Address in January 2007. "Many in this chamber understand that America must not fail in Iraq because you understand that the consequences of failure would be grievous and far-reaching."

The 30,000 additional U.S. troops ultimately proved effective, but cost hundreds of American lives and took a toll on public support for the war.

Less than 500 U.S. service members died in Iraq in 2003; but by the end of 2007, the number approached 4,000.

U.S. and Iraq Sign Security Pact

The U.S. signed a pact with the Iraqi government in November 2008 to leave the country by 2012. And when President Obama took office, he told the American people in February 2009: "Let me say this as plainly as I can: By Aug. 31, 2010, our combat mission in Iraq will end."

On Aug. 31, the Obama administration will change the name of the war, known as "Operation Iraqi Freedom," to "Operation New Dawn." But it isn't expected to signal and end to the war itself.

"I don't think anybody declared the end of the war as far as I know. There's still fighting ahead," the Pentagon's Morell said today.

U.S. Combat Troops in Baghdad 2007

And there are some signs the U.S. could remain in Iraq beyond the end of 2011.

"If I were asked about the withdrawal, I would say to politicians: the U.S. army must stay until the Iraqi army is fully ready in 2020," said the Iraqi military's most senior officer Lt. Gen. Babakir Zebari last week.

While sectarian violence in Iraq has fallen precipitously since 2007, insurgents have ratcheted up attacks on civilians in recent weeks with the Iraqi political situation still in flux after the March parliamentary elections.

It's unclear whether the Iraqi security forces will be able to maintain control of the country with a reduced U.S. presence and while the main Iraqi parties are deadlocked over forming a new government.

Obama Pledges to Withdraw Troops

"President Obama is committed to bringing all troops out by the end of 2011, but it might be the Iraqi government who asks for a presence of U.S. troops to remain," said foreign correspondent and the host of ABC News' "This Week" Christiane Amanpour. "Nobody believes that there will be no forces in Iraq at the end of 2011… because the Iraqi forces are not fully ready to stand up."

At the peak of the U.S. troop "surge" in 2007, more than 160,000 U.S. troops were in Iraq. At least 4,415 U.S. service members have been killed in the Iraq war according to Pentagon.

ABC News' Luis Martinez contributed to this report.