WASHINGTON - America's new enemies in Iraq have been variously described as Baath Party loyalists, "foreign fighters," "terrorists," "criminals" and combinations of all of those.
But in an intelligence void that even U.S. officials acknowledge, little is known about the insurgents' numbers and whether or how they work together. More important, experts are unsure whether the attacks mark the beginning of a national resistance movement, with popular support, that could present a far deadlier challenge to American forces.
"If this is becoming an insurgency of a national character - if that's the case - then 'a long, hard slog' may fall short of defining the challenge that is ahead of us," said Milt Bearden, a former CIA case officer who helped monitor Afghan resistance to the Soviet occupation in the 1980s. "Long, hard slog" was the expression Defense Secretary Donald H. Rumsfeld used in a recent memo to describe what lies ahead in Iraq and Afghanistan.
The toll from this new enemy is obvious in 136 American combat deaths since May 1, the withdrawal of United Nations staff and aid workers, and the choking off of desperately needed investment. Yesterday, Spain announced it was withdrawing much of its diplomatic staff from Iraq for security reasons, the third nation in the U.S.-led coalition to do so.
Although violence has occurred in all parts of the country, U.S. officials say deep-seated resistance to the presence of Americans is limited to a few areas, such as the Sunni Triangle west and north of Baghdad. But American knowledge is limited.
Information about the insurgents is poor in part because of a lack of security and repeated threat of attacks on Americans in Iraq, making it difficult for American agents to get out into the field and cultivate reliable sources, officials say.
This is "a classic occupation problem," said Daniel Byman, a professor at the Georgetown University School of Foreign Service and a Middle East specialist. "Intelligence is always weak at the beginning, yet there is strong pressure to act."
'Allowed to atrophy'
But critics say it is just the latest example of a failure by American intelligence agencies to penetrate the Arab-Muslim world, developing expertise and contacts.
"This is not a capability you build up overnight. It's been allowed to atrophy over a couple of decades," said Andrew Krepinevich, executive director of the Center for Strategic and Budgetary Assessments.
"They're wholly unprepared for this type of activity," a Senate official who follows Iraq closely said of the CIA and other U.S. spy agencies. "They don't know how to do this - infiltrate an entire country, figure out who's running what, who's shooting and who the instigators are."
Iraqi violence is growing increasingly complex, with a wide range of targets, weapons and locations. The insurgents' weapons include suicide bombs, small arms, rocket-propelled grenades, roadside bombs, car bombs, mortars and surface-to-air missiles. In addition to the Sunni Triangle, the attacks have occurred at the American compound in Baghdad, in the Kurdish-dominated north and in the holy Shia cities, Najaf and Karbala.
The violence ranges from gunbattles to the carefully planned bombing of the U.N. headquarters in Baghdad on Aug. 19, which experts say may have drawn on inside knowledge of the workings of the compound.
U.S. officials believe the perpetrators include an uncertain number of Saddam Hussein's Baath loyalists; a "couple of hundred" members of the Kurdish Islamist group Ansar al-Islam; several hundred foreign fighters, including Islamic extremists and "rebels looking for a cause"; and some members of al-Qaida, although officials aren't saying how many or what level of seniority.
"What isn't clear is who is responsible for which attacks," said a U.S. official who spoke on the condition that he not be named. "They may in some instances cooperate in a limited way on logistics," he added. A U.S. military officer in Iraq said foreign forces "clearly are" working with the former Baathists in some cases.
Although Hussein has put out audiotapes championing attacks on the occupation forces, the prevailing view in the U.S. intelligence community is that he is not personally playing a significant role in those attacks.
The U.S. official said there are "pockets of resistance" where "some people are sympathetic to the remnants" of Hussein's regime but insisted that "the majority of the people are supportive of the United States being there and are glad the regime is gone."
Outside the government, close observers see a potential for a national resistance but are split on whether it is developing.
"I really don't see that it's on the verge of becoming national. It's fairly localized," said Phebe Marr, a historian of Iraq. "One of the danger signs to watch for would be cooperation between militant Sunnis and militant Shia."
Osman Faruk Logoglu, Turkey's ambassador to Washington, agreed: The resistance "is still limited to specific groups."
But Robert Baer, a former CIA field officer in the Middle East, said he believes a national insurgency, or popular resistance, is taking shape.
Referring to the missile attack that downed a U.S. helicopter Sunday, killing 16 American soldiers and injuring 20, Baer said, "The people who fired the missile didn't slip in past the local population."
At a minimum, "they're knowing where to hide, and who [can] hide them," said former CIA analyst Judith Yaphe. "I don't think there's any way these groups operate without support or protection in the areas where they're operating.
"They're better organized than we've given them credit for," Yaphe added.
'Wins by not losing'
And they have not only substantial arms and ordnance - in a country awash with weapons - but money. A U.S. military officer based in northern Iraq noted that Odai and Qusai Hussein had $1.3 million in U.S. dollars and Iraqi dinars at the time they were killed. A Fedayeen colonel picked up two nights later had $350,000.
In a country with high unemployment and a monthly wage of $120, this money goes a long way toward hiring mercenary fighters. "A fair number are unemployed who will do just about anything for $100 or even $20," the officer said.
The fact that the insurgency appears to be small and scattered is no indicator of its future strength. Typically, insurgencies start from a position of overwhelming military weakness and little popular support, said Krepinevich. Their weapon is terrorism, and their key advantage is their opponent's ignorance of who and where they are.
"Then they establish guerrilla units, conduct large-scale raids and begin to occupy some territory," he said. At a later stage, "they field large forces." In Iraq, there is a potential for al-Qaida to infiltrate "significant elements," for the skilled Lebanese-based Hezbollah movement to send fighters and for the various groups to coordinate their actions, he said.
"There's an old saying, 'The guerrilla wins by not losing,'" Krepinevich said. Given time, they could take advantage of "the weariness of the Iraqi people, the weariness of the Americans" and "come up with a popular agenda to win over the population."
Signs of Iraqi discontent exist. "The Iraqi people are opposed to foreign troops as such, including Americans," said Logoglu, Turkey's ambassador.
Yaphe, who is a senior fellow at the National Defense University, added, "There are a growing number of disgruntled, frightened people who see no recourse or place for themselves in the new Iraq."
Analysts said American troops in some cases have engendered local hostility with aggressive raids, at times causing unintended casualties. "Every time you kick in a door and roust a family, you've created a revenge group of 40 guys," said one analyst who declined to be identified.
"I've seen film footage in which extended family members said they would need blood money or they would be duty bound to take revenge," said Rosemary Hollis of the Royal Institute of International Affairs in London.
Contributing to unrest, analysts said, are slowness in restoring basic services and in controlling petty crime, signs of profiteering by well-connected firms and the dismantling of the Iraqi military by the occupation authorities. And the prospect that government-owned businesses will be sold to the private sector doubtless unnerves employees.
Baer said that even if only a small percentage of the population is active in the attacks, "the rest are mad about the way things are going."
"People who are fairly secular are becoming anti-American," he said.
The U.S. decision in May to disband the 400,000-member Iraqi army contributed to the unrest by putting a large, armed population out of work, said one U.S. government official.
In such an uncertain environment, large sections of the population that the United States might appeal to may be hedging their bets. "Typically, insurgents can't protect them from the government, and the government can't protect them from insurgents," said Krepinevich.
Logoglu is blunt: "You need a success, and you need it fast."
Sun staff writer Tom Bowman contributed to this article.