Washington ? Al-Qaida is in Iraq to stay.

It’s not a conclusion the White House talks about much when denouncing the shadowy group, known as al-Qaida in Iraq, that used the U.S. invasion five years ago to develop into a major killer.

The militants are weakened, battered, perhaps even desperate, by most U.S. accounts. But far from being “routed,” as Defense Secretary Robert Gates claimed last month, they’re still there, still deadly active and likely to remain far into the future, military and other officials told The Associated Press.

Commanders and the other officials commented in a series of interviews and assessments discussing persistent violence in Iraq and intelligence judgments there and in the U.S.

Putting the squeeze on al-Qaida in Iraq was a primary objective of the revised U.S. military strategy that Gen. David Petraeus inherited when he became the top commander in Baghdad 13 months ago. The goal – largely achieved – was to minimize the group’s ability to inflame sectarian violence, which at the time was so intense that some characterized Iraq as trapped in a civil war.

However, the militants are proving they can survive even the most suffocating U.S. military pressure.

“They are not to be underestimated. That’s one thing I’ve seen over and over,” said Col. John Charlton, commander of the Army’s 1st Brigade, 3rd Infantry Division. His unit has fought al-Qaida for the past 14 months in a portion of Anbar province that includes the provincial capital of Ramadi.

“I’m always very amazed at their ability to adapt and find new vulnerabilities,” Charlton said in a telephone interview this week from his headquarters outside of Ramadi. “They are very good at that,” even though they have largely lost the support of local citizens.

The U.S. and Iraqi government intent is to chip away at al-Qaida until it is reduced to “almost a nonentity,” Army Lt. Gen. Ray Odierno said March 4 shortly after finishing his tour as the No. 2 U.S. commander in Iraq. “Unfortunately with these terrorist organizations, they will always be there at some level.”

Demonstrating anew their remarkable staying power, the militants are thought to be behind attacks in recent days in Baghdad and beyond, including bombings in the capital March 7 that killed at least 68 people.

Now that U.S. troop reinforcements are beginning to go home, Petraeus and the Bush administration will be watching closely to see whether American-trained Iraqi forces can keep up the pressure on al-Qaida.

Al-Qaida in Iraq, which did not exist as a coherent group before U.S. troops invaded in March 2003, probably now numbers no more than 6,000, according to U.S. intelligence estimates. It may have been closer to 10,000-strong before the severe pummeling it took last year, when it lost its main bases of Sunni Arab support. It controls no cities but is still active in pockets through much of central and northern Iraq.

Charlton, whose unit is leaving Iraq shortly and will not be replaced by another U.S. brigade in Anbar, said he is confident of the Iraqis’ determination not to allow al-Qaida back into their communities.

But resilience has been a hallmark of al-Qaida in Iraq, which emerged only after its leader, the Jordanian terrorist Abu Musab al-Zarqawi, pledged his allegiance to Osama bin Laden, leader of the global al-Qaida network, in October 2004. It has survived innumerable reverses in recent years, including al-Zarqawi’s death in a June 2006 U.S. airstrike

The successor to al-Zarqawi is Abu Ayub al-Masri, an Egyptian who keeps a lower public profile.

Brian Fishman, an al-Qaida watcher at the Combating Terrorism Center at the U.S. Military Academy, said that although al-Qaida in Iraq lost some of its “strategic focus” after al-Zarqawi’s death, it remains a threat.

“It’s way too soon to count these guys out,” he said.