Odierno takes over as U.S. commander in Iraq

By Tim Cocks and Andrew Gray

BAGHDAD (Reuters) - General Ray Odierno took command of U.S.-led forces in Iraq on Tuesday, faced with the challenge of ensuring security gains do not unravel at a time when American troop levels are being reduced.

Odierno replaced General David Petraeus at a ceremony presided over by U.S. Defense Secretary Robert Gates, who said the two generals had formed an "incredible team" during the deployment of 30,000 extra U.S. troops to Iraq last year.

The towering, shaven-headed Odierno served as the number 2 U.S. commander in Iraq for 15 months until February.

"He (Odierno) knows that we are at a pivotal moment -- where progress remains fragile and caution should be the order of the day," Gates said in the ornate halls of one of Saddam Hussein's former palaces that is now part of a giant U.S. military base.

Odierno reinforced that message, saying that while Iraq was a different country from two years ago -- when it was on the brink of civil war -- improvements in security were reversible.

The Pentagon will pull 8,000 troops out of Iraq by February, leaving 138,000 soldiers deployed there. All five extra combat brigades sent to Iraq last year completed their withdrawal in July and have not been replaced.

Despite the drop in overall violence in Iraq to four-year lows, the Bush administration has taken a cautious approach to troop cuts and any decision on a major withdrawal will be left to the next U.S. president, who takes office in January.

The Iraqi government wants U.S. troops to withdraw by the end of 2011 under a security deal being negotiated with Washington. Asked if he thought Iraqi forces would be ready to handle security by then, Odierno told reporters:

"We'll see what the agreement says but ... 2011 is the date we're looking towards. I think it has to do with the capacity we're able to build ... I'm cautious in making any judgments at this time."

Odierno added that a key challenge was making sure militant groups could not bounce back.

A female suicide bomber killed 22 people at a dinner celebration for police in Diyala province on Monday, hours after two car bombs killed 12 people in the capital Baghdad.

"FEARSOME BEATING"

Odierno and Petraeus came together last year to implement a new counter-insurgency strategy that helped drive violence down, allowing Iraq to begin seeking foreign investment to rebuild after decades of war and U.N. sanctions.

"Slowly, but inexorably, the tide began to turn. Our enemies took a fearsome beating they will not soon forget," said Gates.

Odierno will face other challenges.