By Leila Fadel | McClatchy Newspapers

BAGHDAD — Nineteen months ago, when Gen. David Petraeus returned to Iraq to take command of the U.S.-led coalition, he toured Dora, a Sunni Muslim district of Baghdad that had been decimated in sectarian fighting, bombings and attacks on Americans, and wondered whether he'd made a big mistake.

"I went the day after taking command. . . . It was horrific. I remember going back and putting my head on my desk and asking myself why in the world I came back," the 55-year-old general said in an interview with McClatchy.

As he hands over the reins of Iraq on Tuesday to his former deputy, Gen. Raymond Odierno, Petraeus is widely credited with a drop in violence in a nation once seen as a lost cause. Markets are bustling in Dora, other areas of Baghdad and elsewhere in the country, and places he wasn't sure could be revitalized have turned around.

Petraeus isn't celebrating victory yet. "Progress may be less fragile than it was when we testified in April. It is nonetheless still fragile and not yet self-sustaining," he said.

There are problems on the horizon, and he also knows that in his new command at the U.S. Central Command he'll have to move forces to Afghanistan, where the Taliban have revived and al Qaida thrives.

As Petraeus began his Baghdad tour, the Bush administration pledged 30,000 more troops in Iraq. Petraeus implemented a counter-insurgency plan, which coincided with a Sunni revolt against the group al Qaida in Iraq. These are the main reasons credited for the drop in violence.

Petraeus did few sit-down interviews with journalists. Instead, he liked to showcase improvements by taking them to markets, drinking sweet cups of tea with Iraqi police officers and soldiers and buying toothpaste at a local store, all great photo opportunities.

But the challenges remain. The government has plans to detain leaders of the Awakening or Sons of Iraq movement, a Sunni-dominated group of tens of thousands of men paid by the U.S. military to help maintain security in their provinces. Some already have been detained or exiled or have fled into hiding.

Major legislation — such as an oil revenue-sharing law, constitutional amendments and a provincial elections law — is still on hold as sectarian political blocs squabble. The fate of the northern oil-rich city of Kirkuk — which Kurds want to absorb into the country's semi-autonomous Kurdish region while most Arab Iraqis oppose the move — could be explosive. Basic services such as electricity and water, hampered by shoddy infrastructure — further damaged by the 2003 U.S.-led invasion and subsequent violence — still aren't being delivered.

Petraeus said he was hopeful that the successes credited to him would continue under his successor, the former Number 2 commander in Iraq.

"I truly believe that General Odierno is exactly the right man for the job," he said. "His experience, his intellect, his ability and his leadership qualities, all of that, all of those elements are ideal. . . . I have complete confidence in him, and will endeavor as the Central Command commander to help him in Iraq, and Ambassador Crocker, in every way that we can." He was referring to Ryan Crocker, the U.S. ambassador to Iraq.

Now Petraeus moves on to challenges at the U.S. Central Command.

"I was in Afghanistan. . . . There's no question about the challenges there," he said, citing the need for additional forces as al Qaida thrives and the Taliban continues its attacks. "That's going to be a huge rock in the rucksack of the future Central Command commander."

MORE FROM MCCLATCHY:

Television crew is slain in northern Iraq

Iraqi government reassures the Awakening, but fighters are wary

Iraqi parliament still gridlocked over provincial-election law

Experts: Bush's Iraq withdrawal small because gains are, too