When the last U.S. combat troops departed Iraq in December 2011, they left behind a defeated al-Qaeda and an Iraq where traditional rivals Sunni and Shiite Muslims were sharing power in the world's only Arab democracy.
Two years later, al-Qaeda has seized major cities where hundreds of U.S. troops died while fighting alongside their Iraqi brethren. The population once freed by the U.S.-Iraqi alliance has now watched those same jihadist insurgents return to command the streets and impose their will.
Indeed, Iraqis are threatened again by civil war over charges of treason and resistance to an authoritarian government. Many significant gains of the 8-year-long Iraq war in which more than 4,400 Americans died have been lost or are now threatened unless swift actions evict the insurgents.
"I fear it's only the beginning and much worse will evolve," says Fred Kagan, a military historian and former adviser to President George W. Bush and U.S. military commander David Petraeus. "And I believe it was avoidable."
The reversal of fortune in Iraq could have a devastating effect on the battle to end militancy and conflict in the Middle East, say analysts and military experts, entangling the West in a new and dangerous front against emboldened jihadists who the U.S. has even recently declared were on the run.
The cities of Fallujah and Ramadi captured this past week by al-Qaeda had been liberated during the Iraq war in the bloodiest combat U.S. troops had seen since Vietnam. The victory left the Iraqi insurgency beaten and humiliated in Anbar province, the heart of the Sunni Muslim homeland that Osama bin Laden himself had claimed would be a graveyard for the hated Americans.
If al-Qaeda reasserts control of Anbar, it will be able to boast of defeating the "Great Satan" while establishing a haven from which to make more trouble: pouring fighters into Syria, threatening the borders of Lebanon and Jordan, and linking up with insurgents in Arab Gulf nations friendly to the United States.
U.S. allies like Israel and Saudi Arabia could quickly be engulfed in such an expanding conflict, analysts say, raising the possibility of a major war in the Middle East with untold death, global oil shocks and, eventually, U.S. military intervention.
"Iraq is not yet lost, but the victory that the United States, our allies and our Iraqi friends achieved at such high cost is now at risk," says Danielle Pletka of the American Enterprise Institute, a public policy think tank.
Critics blame Shiite Prime Minister Nouri al-Maliki for mistreating Sunni political rivals, who in turn tolerate the Sunni terrorists they had turned against during the war. They also say President Obama's pullout of troops made it impossible to lock in the war's gains.
Those failures have emboldened an al-Qaeda that Obama said was "on its heels" and that is not only gaining ground in Iraq but extending its tentacles across the Middle East, according to numerous analysts of the region.
The Obama administration has acknowledged that the terror group responsible for the 9/11 attacks is stepping up operations, yet Obama insists it was time for the Iraqis to defend themselves.
"The president made a commitment to end the war in Iraq," White House spokesman Jay Carney said this week. "He fulfilled that commitment."
Carney said the United States will continue its "important relationship with Iraq" during this crisis and back it up with equipment such as Hellfire missiles and surveillance drones, as well as press Iraq's leaders "to work together" to resolve their differences peacefully.
Colin Kahl, who served as deputy assistant secretary of Defense for the Middle East, says the pullout is not why things have gone awry.
"The root of much of today's turmoil in Iraq is political, and we were not able to resolve Iraq's political disputes with 150,000 troops on the ground over the course of eight years," he says.
IRAQ'S DEMOCRATIC STATE
The 2003 U.S. invasion gave birth to what was the Arab world's only democracy and may have fomented the Arab Spring revolutionary movements that unseated dictators in Egypt and Libya. That development was not just good for Iraqis, but it was seen as a plus for U.S. national security.
Iraq under Saddam Hussein was a violent autocracy that started two major wars, one initiated with an invasion of Kuwait that prompted a U.S. military response in 1991 in Operation Desert Storm. Saddam had the largest army in the region, refused to abide by terms of surrender and supported radical groups.
In 2005, shortly after Saddam's defeat, Iraqis flooded the polls to vote despite death threats from insurgents. The majority population of Shiites and the minority Sunnis and Kurds - traditional rivals - formed a coalition government.
The elections demonstrated "that democracy is just as suitable for Arabs as for other people, and that it was something desired by Arabs," Kagan says.
Because democracies tend not to attack one another, the conversion of a country in the heart of the Middle East from a truculent regime to one that decides matters through politics was hailed in the West. Even Arab writers in the region's capitals began openly questioning why they should not have the same benefit.
But that harmony is "very much at risk," Kagan said.
Many lay the blame on al-Maliki, who moved against his Sunni opponents in harsh ways. His government issued murder and terrorism charges against his Sunni vice president, Tarik al Hashemi, alleging he was supporting insurgents. Last year, he brought corruption charges against his then-finance minister, Rafi al-Issawi, a Sunni.
Sunnis initially reacted by holding sit-ins around the country, though with little effect.
Shadi Hamid, director of research for Brookings Doha Center, says the U.S. did not apply enough pressure at the time for al-Maliki to change course and avert the crisis in Iraq today.
Obama had put Vice President Biden in charge of overseeing many Iraqi affairs when he entered office in 2009, but a U.S. commitment to use diplomatic and aid programs to maintain comity between the government factions was never carried out, Hamid says.
Administration support for promoting democracy strengthened in 2011 after the first uprisings of the Arab Spring and the return of militancy to Iraq. But Hamid says the help was minimal and soon dissipated.
Pulling the U.S. presence out "was the No. 1 goal," Hamid says. "There was less thought to the potential fallout or how to manage that withdrawal to protect the health of Iraqi democracy going forward."
Max Boot, a military historian at the Council on Foreign Relations, says Obama can prod al-Maliki to reverse course by making the intelligence and military aid the prime minister has requested of Washington contingent upon loosening his grip on power.
The White House insists it is doing so, and Secretary of State John Kerry said last week that the U.S. will stand with the government of Iraq.
Michael Knights, a military specialist at The Washington Institute for Near East Policy, says not all the progress has been lost. Iraq's oil sector surpassed Iran's to become OPEC's second-largest producer, and new laws protect ethnic and religious minorities.
"Some things have been lost," says Knights. "Some things were also never truly gained, such as social harmony."
A STRATEGIC U.S. PRESENCE
The United States was on the verge of creating a permanent military presence in Iraq when the war ended.
That would have provided a base from which to strike al-Qaeda in its backyard and counter Iranian influence in the region, analysts say. Case in point: The United States still has 40,000 troops in Japan and 54,000 in Germany a half-century after World War II ended. U.S. commanders under Obama recommended keeping 20,000 troops in what was deemed a more volatile area of the world. Commanders said a robust troop presence would help Iraqi forces keep a lid on violence and allow the U.S. to keep tabs on al-Qaeda. Obama rejected the idea, Kagan said.
"The resurgence of al-Qaeda in Iraq that we're seeing is a direct result of the withdrawal of U.S. forces because Iraqi security forces don't have the high-end counterterrorism capabilities that U.S. forces had," he said.
Kahl says Obama was willing to leave a smaller force in place but that Iraqi politicians balked. Sen. John McCain has said the White House did not try to settle the differences because Obama was set on an exit.
Lacking precise targeting intelligence and strike capabilities, Iraqi forces have resorted to mass arrests and indiscriminate assaults to root out militancy following the American departure. This has exacerbated Sunni grievances against the government.
The acrimonious split in the Islamic world that created Sunni Muslims and Shiite Muslims goes back centuries and is said by many analysts to be the reason for instability and radicalism in the Arab world.
In practically every Arab state, one branch dominates the other. But the power-sharing arrangement in Iraq provided a shining example that the age-old animosities at the root of so much violence can be quelled, says Stephen Biddle, an analyst at the Council on Foreign Relations.
Yet al-Maliki, a Shiite, has always been nervous about sharing power with Sunnis, who were allies of Saddam, Biddle says.
"He doesn't trust them and he's very wary about sharing power with them," Biddle says.
In April, parliamentary elections are to be held in which Sunnis expect to gain a fair share of seats. If they don't, that may be the end of the dream coalition.
"The Maliki government's likely attempt to manipulate election results and shore up his base among Iraqi Shiites may further alienate Sunni Muslims," Daniel Byman, a senior fellow at the Saban Center for Middle East Policy, warned Congress recently. "As Sunni Muslims feel increasingly ostracized, such frustrations may translate into even broader popular support for (al-Qaeda) inside Iraq."
A MESSAGE LOST
U.S. forces delivered al-Qaeda a crushing defeat in Iraq, achieved through Petraeus' counter-insurgency doctrine in which Sunnis already chafing under al-Qaeda strictures were bolstered and persuaded to join the U.S. in forcing out the terrorists.
It was a stake through the heart of the Sunni al-Qaeda movement to have been undone by its own branch of Islam.
But al-Maliki's lingering distrust of the Sunnis led to him turning to a Shiite-led security apparatus. This alienated the Sunni minority and contributed to al-Qaeda recruiting in Iraq and abroad, Knight says.
Now, U.S. forces, which could systematically decimate al-Qaeda targets, are gone.
"It's not just Maliki saying don't do it," Knight says. The Obama administration's mandate was to end the war, "and anything that smacks of going back in is not acceptable," he says. "So we basically lost the ability to kill al-Qaeda in one major country."
Carney claims those who criticize the White House wish U.S. forces were still fighting in Iraq, even though polling has shown that Americans have no interest in doing so.
"Through the enormous courage and sacrifice of our armed forces, as well as the efforts of our diplomatic personnel, we have provided enormous opportunity to Iraq to move forward and find a peaceful resolution to sectarian conflicts, and to unify behind democratic goals and shared prosperity," Carney said.
But Kagan says what Obama fails to grasp is that the national security of the United States is at risk if Iraq fails to defeat al-Qaeda and succeed as a democracy. The Iraq war sent a message to the Arab world that the United States would stand with Muslim partners in this cause.
"That commitment was lost when we withdrew all our forces," Kagan says. It declared the new president's disinterest in the Arab world, and sent Iraqis and other Arabs in the region a new message: "You're on your own."