10 Years After the Iraq Invasion

March 19, 2013 -- The 10th anniversary of the start of the U.S. war in Iraq is a muted affair with no official commemorations planned in either Washington or Baghdad. Instead, the anniversary continues to draw the same lingering questions of the past decade, namely was the war in Iraq worth fighting.

The fallout continued today, the 10th anniversary, with a wave of bombings that killed at least 59 people in Baghdad and injured 221 others, according to police. The war has also taken the lives of 4,488 U.S. service members and left more than 32,000 wounded.

See More: A Look Back On The Iraq War

Any pessimism is in contrast to 2003, when military victories on the battlefield buoyed hopes that U.S. military forces might return home soon. But U.S. troops ended up staying for almost nine years as Iraq's security situation deteriorated into a civil war. In the end, the last U.S. combat troops did not leave Iraq until December 2011.

RELATED: ABC's Bob Woodruff on Iraq 10 Years Later

Within a few years of the invasion, Iraq spiraled into chaos, fueled by a growing insurgency and the increasingly deadly sectarian fighting between Sunnis and Shiites. Tens of thousands of Iraqi civilians lost their lives, with some estimates as high as 100,000.

Although the level of violence is no longer what it was when the U.S. military was in Iraq, terrorist bombings are still a common occurrence in Iraq. It is believed that as many as 200 Iraqis died in violent attacks in February.

RELATED: 10-Year Iraq War Timeline

And the divide between Sunnis and Shiites is reflected in the political stalemate generated by the increasingly authoritarian government of Iraqi Prime Minister Nouri al-Maliki, a Shiite.

But in 2003, the world's attention was focused on whether Saddam Hussein would give into U.S. and international pressure to give up the weapons of mass destruction he was believed to possess.

Within a year after the invasion, it became clear that Hussein's regime did not possess weapons of mass destruction. Congressional investigations determined that the Bush administration had made the decision to rid Iraq of the weapons based on a huge intelligence failure. Iraq had no such weapons. Hussein had disassembled his chemical and nuclear programs years before, but had kept even his own generals guessing about what his regime possessed.

The American public's skepticism of whether the U.S. invasion should have been launched in the first place began to increase as the occupation continued and the number of American casualties continued to spike.

Ten years after the start of the war, a majority of Americans now believe the war in Iraq was not worth the cost. An ABC News-Washington Post poll released this week showed 58 percent of those polled believed the war in Iraq was not worth the fight.

Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, served three years in Iraq and he believes it was worth fighting. During an appearance Monday at a Washington think-tank, he said the invasion and the occupation were worth the cost because they provided the Iraqi people with "an incredible opportunity" and has provided the United States "with a partner, not an adversary."

Dempsey said he understands that the debate about the war continues. "It will go on and should go on," Dempsey said. "We should always be introspective about the things we do.

"There is no longer the strong man, the dictator and the threat to the region by the name of Saddam Hussein that there was."

He said the war gave "the Iraqi people an incredible opportunity" and whether that path was "a clean path" or "one fraught with missteps, opportunities gained, opportunities lost, the point is we really did give them an opportunity.

"And today we have in Iraq, we have a partner, not an adversary," he added.

In an interview with ABC News' Martha Raddatz, retired General Peter Chiarelli, the number-two U.S. general in Iraq as the sectarian violence exploded , said he has "got to believe" that the war in Iraq was worth the sacrifice the United States made.

Chiarelli recalls writing more than 500 letters to the families of fallen U.S. service members in 2006 as the sectarian violence in Iraq spun out of control.

He said he saw things "no one should ever see" as the violence increased in 2006.

"We saw murders every single night. We didn't really see them at night, we saw them in the mornings when we went on patrol," he said. "We would find men with hands tied behind their back and shot between the eyes, and there were days where we would find a hundred bodies out in the streets of Baghdad."

Iraqi Prime Minister Maliki was recently quoted as having said the U.S. effort helped establish democracy in his country.

In the Special Inspector General for Iraqi Reconstruction's final report on the haphazard U.S. reconstruction effort, Maliki is described as concluding an interview with their "gratefully, observing that the reconstruction program contributed to an ultimately successful U.S. effort to establish democracy in Iraq."

According to the report, Maliki said, "This money and the blood that was shed here is part of the price [paid by] the United States of America in cooperation with Iraq to fight terrorism ... and establish the Strategic Framework Agreement."

Today, Iraqi politics continues to reflect the divide between Sunnis and Shiites.

When the war started in March, 2003 few resources were dedicated to a post-war reconstruction effort. Eventually, the U.S. spent $60 billion to rebuild Iraq and the special inspector general estimated in its report that at least $8 billion of it might have been wasted. The Pentagon estimates that the long-term U.S. military presence in Iraq cost $728 billion.

Military plans called for the ground invasion of Iraq to begin March 21, 2003, after the start of an hours-long, air-bombing campaign over Baghdad intended to convey "shock and awe."

Those plans were carried out as scheduled, but by then the war was already two days old.

The war had begun the night of March 19, 2003, with a hastily planned bombing attack on a farm south of Baghdad where fresh intelligence indicated Hussein might be hiding. Years later, that intelligence was also proven to have been inaccurate.

In a televised address that night, President George W. Bush told the nation, "My fellow citizens, at this hour, American and coalition forces are in the early stages of military operations to disarm Iraq, to free its people and to defend the world from grave danger."

Bush warned that the military campaign "could be longer and more difficult than some predict. And helping Iraqis achieve a united, stable and free country will require our sustained commitment."

Within a few weeks, U.S. troops were in Baghdad and the fall of one of Hussein's statues symbolized the hope for a new start in Iraq.

But a few months later, when U.S. officials disbanded Hussein's army, an American military adept at launching a large-scale conventional invasion quickly found itself ill-prepared for the task of providing security in the face of a growing insurgency fueled by Hussein's former soldiers.

In time, the military adopted a counterinsurgency strategy that in 2007 led President Bush to order the "surge" of additional troops to Iraq. At the peak of the surge in late 2007, the number of U.S. troops in Iraq numbered 170,000, almost 100,000 more troops than the initial invasion force in 2003.

For U.S. military leaders, Iraq provided some important and hard-fought "lessons learned" about how the military should prepare for future conflicts. Among them was that the U.S. military should include counterinsurgency training in the future and the recognition that planning for post-combat occupations should be remain a priority.

That wisdom was soon communicated throughout the military.

In February 2011, then-Defense Secretary Robert Gates told Army cadets at West Point that the military should plan for all kinds of military conflict in the future.

"In my opinion, any future defense secretary who advises the president to again send a big American land army into Asia or into the Middle East or Africa should 'have his head examined,' as General [Douglas] MacArthur so delicately put it.

"The odds of repeating another Afghanistan or Iraq -- invading, pacifying and administering a large Third World country -- may be low," Gates said.

He added that the U.S. should work to prevent "festering" international problems "from growing into full-blown crises which require costly -- and controversial -- large-scale American military intervention."