US soldiers wave at their comrades as they cross the border between Iraq and Kuwait.
The last US forces left Iraq and entered Kuwait on Sunday, nearly nine years after launching a divisive war to oust Saddam Hussein, and just as the oil-rich country grapples with renewed political deadlock.
The last of roughly 110 vehicles carrying 500-odd troops mostly belonging to the 3rd Brigade, 1st Cavalry Division, crossed the border at 7:38 am (0438 GMT), leaving just a couple hundred soldiers at the US embassy, in a country where there were once nearly 170,000 troops on 505 bases.
It ends a war that left tens of thousands of Iraqis and nearly 4,500 American soldiers dead, many more wounded, and 1.75 million Iraqis displaced, after the US-led invasion unleashed brutal sectarian killing.
"It feels good, it feels real good" to be out of Iraq, Sergeant Duane Austin told AFP after getting out of a "Mine Resistant, Ambush Protected" (MRAP) vehicle in Kuwait.
"It's been a pretty long year -- it's time to go home now."
The 27-year-old father-of-two, who just completed his third deployment to Iraq, added: "It's been a long time, coming and going. It's been pretty hard on all of us. ... (It will) be a nice break to get back, knowing that it's over with now."
The last group of vehicles transporting US troops out of Iraq left the recently handed over Imam Ali Base outside the southern city of Nasiriyah at 2:30 am to make the 350-kilometre (220-mile) journey south to the Kuwaiti border.
They travelled down a mostly-deserted route, which US forces paid Shiite tribal sheikhs to regularly inspect to ensure no attacks could take place.
Five hours later, they crossed a berm at the Kuwaiti border lit with floodlights and ringed with barbed wire.
"I am proud -- all Iraqis should be proud, like all those whose country has been freed," 26-year-old baker Safa, who did not want to give his real name, told AFP in Baghdad. "The Americans toppled Saddam, but our lives since then have gone backward."
The withdrawal comes as the country struggles with renewed political deadlock as the Iraqiya bloc, which emerged as the largest in March 2010 polls and drew most of its support from minority Sunni Arabs, said it was boycotting parliament to protest Prime Minister Nuri al-Maliki's centralization of decision-making.
The bloc, which controls nine ministerial posts, has not, however, pulled out of Iraq's national unity government led by Maliki, a Shiite.
"We can no longer remain silent about the way the state is being administered, as it is plunging the country into the unknown," the bloc, which holds 82 seats in the 325-member parliament, said in a statement on Saturday.
Iraqiya said the government's actions, which it claimed included stationing tanks and armored vehicles outside the houses of the bloc's leadership in the heavily-fortified Green Zone, "drives people to want to rid themselves of the strong arm of central power as far as the constitution allows them to."
Provincial authorities in three Sunni-majority provinces north and west of Baghdad have all moved take up the option of similar autonomy to that enjoyed by Kurds in north Iraq, drawing an angry response from Maliki.
Key political issues such as reform of the mostly state-run economy and a law to regulate and organise the lucrative energy sector also remain unresolved, to say nothing of an explosive territorial dispute between Arabs and Kurds centered around the northern oil hub of Kirkuk.
Sunday's completion of the withdrawal brings to a close nearly nine years of the American military involvement in Iraq, beginning with a "shock and awe" campaign in 2003 to oust Saddam, which many in Washington believed would see US forces conclude their mission in Iraq within months.
But key decisions taken at the time have since been widely criticized as fuelling what became a bloody Sunni Arab insurgency, in particular dissolving the Iraqi army and purging the civil service of all members of Saddam's Baath Party, including lower-ranking members.
The insurgency eventually sparked communal bloodshed, particularly after the February 2006 bombing of a Shiite shrine in the predominantly Sunni city of Samarra by Al-Qaeda.
More than 100,000 Iraqis have been reported killed in violence since the invasion, according to British NGO Iraq Body Count.
The bloodshed was only quelled when then-US president George W. Bush ordered a "surge" of American troops to Iraq, and Sunni tribal militias sided with US forces against Al-Qaeda.
Baghdad and Washington signed a 2008 pact that called for the withdrawal by the end of this year, and in the summer of last year, the US declared a formal end to combat operations while maintaining fewer than 50,000 troops in Iraq.
The US embassy will now retain just 157 US soldiers, for training of Iraqi forces, and a group of Marines to secure the diplomatic mission.
Attacks nationwide, meanwhile, remain common, but violence in Iraq has declined significantly since its peak.
Iraq has a 900,000-strong security force that many believe, while capable of maintaining internal security, lacks the means to defend its borders, airspace and territorial waters.
Some observers also fear a return to bloody sectarianism, doubt the strength of Iraq's political structures, and feel that Maliki has entrenched his power base to the detriment of the country's minorities.