The U.S. intelligence focus on Iraq's nonexistent weapons of mass destruction may have contributed to the Bush administration's failure to anticipate the insurgency that followed the U.S. invasion, former Iraq administrator L. Paul Bremer said Tuesday.

"The fact that there would be some resistance was anticipated. What really caught us by surprise was its intensity," Bremer told a Manhattan audience, when questioned about why U.S. leaders mistakenly expected a friendlier reception in Iraq.

"I suppose an argument would be that the intelligence resources were almost entirely devoted to WMD and not to this question of the insurgency," he said.

The ex-diplomat, Iraq's occupation chief in 2003-2004, spoke as part of a promotional tour for his memoir of his 14 months in Baghdad, "My Year in Iraq."

In his book, Bremer complains that too many U.S. intelligence resources were expended for too long in 2003 on the hunt for Iraqi unconventional arms, the stated reason for the U.S. invasion. He notes that in mid-2003 the weapons hunters, the Iraq Survey Group, had a staff of 1,400 intelligence analysts and others.

But the futile WMD hunt went on for many months after the insurgency gained strength before intelligence officers were finally shifted over to working on the insurgency.

On a related subject, Bremer told Tuesday night's audience he does not expect a major drawdown of U.S. troops from Iraq in 2006.

When James F. Hoge, the host and editor-in-chief of the journal Foreign Affairs, suggested some believe as many as 50,000 troops might be withdrawn this year, Bremer demurred.

"I would be very surprised if he (President Bush) is operating on a number like 50,000," Bremer said.

The Pentagon thus far has announced a drawdown of only 7,000 troops, which would cut the number of U.S. military in Iraq to about 130,000 by March.

"We would all like the Iraqis to be more and more responsible for their own security," Bremer said. But, he said, "they've got a ways to go."