BAGHDAD -- A war has probably never been so debated and so little understood as the one in Iraq. "The domestic political debate has nothing to do with what we're doing here," says one U.S. officer, in a representative comment offered not in a spirit of bitterness, but of cold fact.

This is the lonely war. No one cares about it as much or understands it as well as the men and women here on the ground, who feel -- understandably -- that they are the only ones even remotely engaged in the fight.

The U.S. government has never brought to bear its resources in a truly national effort to win; the State Department has left almost the entire nonmilitary aspect of the war to the military; the Pentagon's slow-moving procurement program has an internal clock still set to peacetime; the top brass worry more about relieving the strain on the ground forces than achieving success on the ground; and the Bush administration hasn't been willing -- until too late -- to begin to provide a bigger force that would relieve that strain.

On top of this are the members of Congress and senators who show up for visits that seem more about saying they have been to Iraq than truly grappling with the war; the journalists whose reports tend to reflect whatever is the conventional wisdom about the war back in their newsrooms; and supporters and opponents of the war who support their clashing narratives of victory and defeat with the gross simplifications.

The word that one hears again and again here, but is so rare in the domestic political debate, is "complex." The war is changing at least every six months, and every area of the country -- even every neighborhood in Baghdad -- has a different dynamic. An officer at Forward Operating Base Justice in northwestern Baghdad explains that one translator who works there has to take three or four different taxis to get to the base, with a different faction ready to kill him from neighborhood to neighborhood.

Sometimes our supposed allies in the Iraqi National Police work against us, and sometimes our enemies can be leveraged against our even-more-lethal enemies. Navigating this multidimensional, ever-shifting chessboard are the leaders of U.S. combat brigades who have to run local governments, train Iraqi forces, manage relations with Baghdad and engage in graduate-level anthropology -- all while fighting a war.

South of here in the rural Sunni area known as the "Triangle of Death," there are 137 tribes and subtribes -- what an officer of the 2nd Brigade of the Army's 10th Mountain Division calls "an archipelago of complex societal islands." We have begun to master them. The tribes have produced thousands of volunteers to police the area, and violence has plummeted. But the story hasn't gotten out. Troops laugh about a reporter who refused to get off an aircraft upon learning that it had alighted in the dreaded Triangle of Death.

That kind of disconnect with press coverage and the debate back home is a constant theme. The Senate recently passed a resolution sponsored by Sen. Joe Biden, D-Del., calling for splitting Iraq in three. A colonel here scoffs that the Senate managed to agree on the one step that basically no one in Iraq wants to take.

President Bush doesn't seem much more relevant. In discussions of what motivates Iraqis, Bush's favorite theme of freedom never comes up. It's always survival, fear, power or pride, or some combination of all of them. Bush has been famously resolute, but one wonders how much -- even after four grueling years -- he truly understands the war on which he has staked his presidency.

Americans here don't talk so much of victory, but of achieving an acceptable outcome and forestalling the catastrophe that failure would bring. The burden for doing that falls, of course, on our troops, who have managed for now to reverse Iraq's downward slide. They might be lonely, but they are brilliant and unbelievably brave.