WASHINGTON — American forces in Iraq have often been accused of being slow to apply hard lessons from Vietnam and elsewhere about how to fight an insurgency. Yet, it seems from the outside, no one has shrugged off the lessons of history more decisively than the insurgents themselves.
The insurgents in Iraq are showing little interest in winning hearts and minds among the majority of Iraqis, in building international legitimacy, or in articulating a governing program or even a unified ideology or cause beyond expelling the Americans. They have put forward no single charismatic leader, developed no alternative government or political wing, displayed no intention of amassing territory to govern now.
Rather than employing the classic rebel tactic of provoking the foreign forces to use clumsy and excessive force and kill civilians, they are cutting out the middleman and killing civilians indiscriminately themselves, in addition to more predictable targets like officials of the new government. Bombings have escalated in the last two weeks, and on Thursday a bomb went off in heavy traffic in Baghdad, killing 21 people.
This surge in the killing of civilians reflects how mysterious the long-term strategy remains - and how the rebels' seeming indifference to the past patterns of insurgency is not necessarily good news for anyone.
It is not surprising that reporters, and evidently American intelligence agents, have had great difficulty penetrating this insurgency. What is surprising is that the fighters have made so little effort to advertise unified goals.
Counter-insurgency experts are baffled, wondering if the world is seeing the birth of a new kind of insurgency; if, as in China in the 1930's or Vietnam in the 1940's, it is taking insurgents a few years to organize themselves; or if, as some suspect, there is a simpler explanation.
"Instead of saying, 'What's the logic here, we don't see it,' you could speculate, there is no logic here," said Anthony James Joes, a professor of political science at St. Joseph's University in Philadelphia and the author of several books on the history of guerrilla warfare. The attacks now look like "wanton violence," he continued. "And there's a name for these guys: Losers."
"The insurgents are doing everything wrong now," he said. "Or, anyway, I don't understand why they're doing what they're doing."
Steven Metz, of the Army War College Strategic Studies Institute, said the insurgency could still be sorting itself out. Yet, he said, "It really is significant that even two years in there hasn't been anything like any kind of political ideology or political spokesman or political wing emerging. It really is a nihilistic insurgency."
He warned that this hydra-headed quality could make the insurgents hard to crush, even as the lack of unity makes it unlikely they will rule Iraq. "It makes it harder to eradicate the insurgency, but it also makes it more difficult for insurgents to gain their ultimate objective - if that is to control the country," he said.
That no one knows if that is the objective is, by historical standards, one of several remarkable, perplexing features of this fight.
A clear cause - one with broad support - is usually taken for granted by experts as a prerequisite for successful insurgency.
But insurgents in Iraq appear to be fighting for varying causes: Baath Party members are fighting for some sort of restoration of the old regime; Sunni Muslims are presumably fighting to prevent domination by the Shiite majority; nationalists are fighting to drive out the Americans; and foreign fighters want to turn Iraq into a battlefield of a global religious struggle. Some men are said to fight for money; organized crime may play a role.
This incoherence is something new. "If you look at 20th-century insurgencies, they all tend to be fairly coherent in terms of their ideology," Dr. Metz said. "Most of the serious insurgencies, you could sit down and say, 'Here's what they want.' "
In Iraq, insurgent groups appear to share a common immediate goal of ridding Iraq of an American presence, a goal that may find sympathy among Iraqis angry about poor electricity and water service and high unemployment.
Average Iraqis may distinguish among the groups within the insurgency and their tactics. Still, the insurgents haven't publicly proposed a governmental alternative, and their anti-American message has been muddied by their attacks on civilians and by the election of an Iraqi government that has not asked the Americans to leave.
If the insurgency is trying to overthrow this regime, it is contending with a formidable obstacle that successful rebels of the 20th century generally did not face: A democratically elected government. One of the last century's most celebrated theorists and practitioners of revolution, Che Guevara, called that obstacle insurmountable.
"Where a government has come to power through some form of popular vote, fraudulent or not, and maintains at least an appearance of constitutional legality," he wrote, "the guerrilla outbreak cannot be promoted, since the possibilities of peaceful struggle have not yet been exhausted."
The insurgents' choice of adversary is unusual. But the recent surge in violence at least follows a time-tested pattern. The insurgents are apparently trying to swamp any progress toward stability with evidence and images of chaos. The killing in that time of at least 250 policemen, soldiers and recruits also fits a pattern, since insurgents have customarily made targets of accused collaborators to isolate a regime. Less obvious is the goal in the killing of some 150 civilians.
The relationship between insurgents and the general population is always complex. Mao Zedong famously postulated that guerrillas move among the people as fish move through water. But he also warned that "a revolution is not a dinner party," and many insurgents, including the Vietcong, effectively used terror - often selectively applied - against civilians to compel segments of the population into at least passive support.
From his experience fomenting Arab revolt against the Turks, T. E. Lawrence concluded that insurgents needed only 2 percent active support from the population, and 98 percent passive support.
What is curious about the Iraqi tactic is that it appears aimed at creating active opposition. The insurgency is powered by Sunnis; the civilians they have killed have been overwhelmingly Shiites and Kurds. The goal appears to be to split apart the fragile governing coalition and foment sectarian strife.
Yet if the insurgents achieve all-out civil conflict, the likely losers are the Sunnis themselves, since they are a minority. Having governed for decades in Iraq, Sunnis are accustomed to the whip hand and may simply assume they will be able to regain control. Or perhaps they are betting that chaos will lead to partition, allowing Sunnis to govern themselves.
David Galula, author of a systematic 1964 study, "Counterinsurgency Warfare: Theory and Practice," noted the effectiveness of force and intimidation as tools of an insurgency. But he added a crucial caveat: "There is, of course, a practical if not ethical limit to the use of force; the basic rule is never to antagonize at any one time more people than can be handled."
That was one of several mistakes that the Communist rebels made in Greece in the late 1940's. Once the country was liberated from the Germans, the Communists had no majority cause, and they chose to confront a democratically elected government. Lacking much industry, Greece had few proletarians, and the peasants were not particularly restive.
Not that the Communists cared. They had contempt for the peasants and alienated them further by extorting food and reinforcements through threats and executions. They burned villages in hopes of making the peasants a burden on the American-backed government and crippling the Greek economy.
THE guerrillas benefited from support from the Communist dictatorships to Greece's north. Then, in July 1949, Tito shut the Yugoslav border, eliminating Yugoslavia as a sanctuary. But Professor Joes argued that, by then, the insurgents were doomed anyway. "They had already shot themselves in the feet and both knees," he said. In Iraq, American and Iraqi troops have embarked on an offensive in the west partly in hopes of cutting off what the military command says is a flow of foreign fighters and matériel across the Syrian border. But military experts say that without stationing thousands of troops along the border, the military has little chance of closing it off.
If the immediate objective of the insurgents is relatively limited - not to topple the government and drive the Americans out now but to pin them down and bleed them - that at least would have solid precedents. As the counterterrorism expert Bruce Hoffman noted in a paper for Rand last year, "For more than 30 years, a dedicated cadre of approximately 200 to 400 I.R.A. gunmen and bombers frustrated the maintenance of law and order in Northern Ireland, requiring the prolonged deployment of tens of thousands of British troops." Yet the I.R.A. is still far from its larger goal: to drive the British out.
Among Iraq's insurgents, the jihadists are one group that has suggested a sweeping goal. They want to establish a new caliphate - a religious regime with expansive boundaries. For them, the destruction and chaos in Iraq may represent creative forces, means of heightening the contrasts among sects, religions and whole civilizations. Searching for parallels, several experts compared the insurgents in Iraq to the violent anarchists of the late 19th and early 20th centuries. That movement took root among the alienated and uprooted who could find no place in modern society.
Yet it may prove to be one of history's humbling lessons that history itself fails to illuminate the conflict under way in Iraq. No one really knows what the insurgents are up to.
"It clearly makes sense to the people who are doing it," said Dr. Loren B. Thompson, a defense analyst at the Lexington Institute. "And that more than anything else tells us how little we understand the region."