US lawmakers have been seeking ways to prevent a repeat of intelligence failures leading to the September 11, 2001, terrorist attacks on the United States as well as the embarrassment of not finding chemical and biological weapons in Iraq as expected.

"There are no quick answers here. We very much want to do a strategic and structured approach," said Representative Peter Hoekstra of Michigan. "This is important stuff and we want to get it right."

President George W. Bush in December signed a law authorizing an overhaul of US intelligence agencies. The law, based on the findings of an investigation into the September 11 attacks, mandated improved coordination between agencies and consolidated authority over budgets in the hands of a new national intelligence director.

Hoekstra, a Republican who heads the House of Representatives Intelligence Committee, has scheduled a series of hearings to evaluate how US spy agencies can better respond to the threats facing the United States.

Lawmakers are also awaiting an internal Central Intelligence Agency report on its handling of intelligence about terrorist groups leading up to the September 11 attacks.

The September 11 investigation, and a subsequent congressional probe of intelligence used to justify the US-led invasion of Iraq in 2003, both faulted the CIA's handling of critical information, and some experts say the agency still has not adapted to the demands of dealing with terrorist groups and the regimes that support them.

"I think we have real quality control problems," Richard Perle, a former assistant defense secretary and Pentagon adviser, told the committee Wednesday.

"We don't pay nearly enough attention to open-source material. We put a tremendous emphasis on information that we can steal, somehow believing that if we've stolen it must be authentic. And if we've only discovered it by reading novels and newspapers, it can't possibly be valuable."

Perle, former CIA director James Woolsey and Michael Swetnam, another former intelligence official, all said US spy agencies should place more emphasis on understanding the culture in which Islamist militants operate, just as the CIA did with the Soviet Union during the Cold War.

"We need to rethink cultural intelligence, bring it back into vogue and invest in it," Swetnam said.

"It's time to put money once again in academia and in not-for-profit institutions to study Islamic radicalism, fundamentalism around the world, the global economy, the spreading of technology."

Perle said US spy agencies have repeatedly failed to understand the threat posed by militant Islam and Iran's nuclear ambitions because they emphasize the skills of the spy game over understanding the cultures and ideologies of the Middle East. That overly narrow focus has blinded US planners and limited the nation's options against those threats, he said.

"The history of the intelligence community's assessment -- and for that matter, operations -- in the Arab world, and in the Gulf, in particular, has been appallingly inadequate for many, many years," he said.

Woolsey is chairman of Freedom House, which last week released a report saying Saudi Arabia, a US ally dominated by a fundamentalist brand of Islam known as Wahhabism, has financed the flow of hate literature into the United States for years, but the activity has received scant attention from authorities.

He called the spread of Wahhabism "a serious problem" reminiscent of the spread of communism during the Cold War.

"Not all Wahhabis become Islamist terrorists, but that is the soil in which Islamist terrorism, such as Al-Qaeda, grows, very much like the angry German nationalism of the (1920s) and early (1930s) was the soil in which Nazism grew," Woolsey said.

"One of the major frontiers of intelligence, and intelligence collection and understanding our enemy in the months and years to come, will be understanding how to deal with this link between Wahhabi ideology and Islamist terror."

US knowledge of North Korea's nuclear program and its military decision-making process is also lacking, even though US spy agencies have done a good job of understanding some of the bizarre habits of that country's Stalinist leader, Kim Jong-Il, said Asia expert Kurt Campbell, of the Center for Strategic and International Studies.

"On the critical issues that matter the most about North Korea, I'm afraid we know very little," he said.