Think "light at the end of the tunnel". Think the era of Lyndon B Johnson. Think of that flood of positive numbers - the "metrics" of victory - that came pouring out of Vietnam and now, in the form of numbers of troops armed and trained for the new Iraqi army, police and security forces, is flooding out of Iraq.

Top generals back in Washington all lend a helpful hand. (Joint Chiefs Chairman General Richard Myers: "Well, first of all, the number of incidents is actually down 25% since the highs of last November, during the election period. So, overall, numbers of incidents are down. Lethality, as you mentioned, is up ... I think what's causing it is a realization that Iraq is marching inevitably toward democracy.") Hang in there, Secretary of State Condoleezza Rice similarly assured just the other night, it's like the period after World War II when we occupied Germany and Japan; it takes patience and time to implant democracy in a defeated country. The growing strength of the insurgency, Washington officialdom has been officially saying this past month in all sorts of ways, is but proof of the progress we're making. It's just the "last gasp" of a dying movement.

Meanwhile, in Iraq, American officers fighting the war tell another story to reporters. Senior officials now claim not so privately "that there is no long-term military solution to an insurgency that has killed thousands of Iraqis and more than 1,300 US troops during the past two years". Brigadier General Donald Alston, the chief US military spokesman in Iraq, commented to reporter Tom Lasseter of Knight Ridder, "I think the more accurate way to approach this right now is to concede that ... this insurgency is not going to be settled, the terrorists and the terrorism in Iraq is not going to be settled, through military options or military operations".

Lieutenant Colonel Frederick P Wellman, who works with the task force overseeing the training of Iraqi security troops, told Lasseter, "the insurgency doesn't seem to be running out of new recruits, a dynamic fueled by tribal members seeking revenge for relatives killed in fighting. 'We can't kill them all', Wellman said. 'When I kill one I create three'." General George W Casey, top US commander in Iraq, called the military's efforts "the Pillsbury Doughboy idea" - pressing the insurgency in one area only causes it to rise elsewhere.

Down even closer to the ground, American soldiers are blunter yet: "I know the party line. You know, the Department of Defense, the US Army, five-star generals, four-star generals, President Bush, [Secretary of Defense] Donald Rumsfeld: The Iraqis will be ready in whatever time period," said 1st Lieutenant Kenrick Cato, 34, of Long Island, New York. "But from the ground, I can say with certainty they won't be ready before I leave. And I know I'll be back in Iraq, probably in three or four years. And I don't think they'll be ready then."

"I just wish [the Iraqi troops would] start to pull their own weight without us having to come out and baby-sit them all the time," said Sergeant Joshua Lower, a scout in the Third Brigade of the First Armored Division who has worked with the Iraqis. "Some Iraqi special forces really know what they are doing, but there are some units that scatter like cockroaches with the lights on when there's an attack."

And in the meantime, in the opinion polls, slowly but inexorably public support for the war continues to erode. As Susan Page of USA Today reports in a piece ominously headlined, "Poll: USA Is Losing Patience on Iraq", "Nearly six in 10 Americans say the United States should withdraw some or all of its troops from Iraq, a new Gallup Poll finds, the most downbeat view of the war since it began in 2003."

Does no one remember when this was the story of Vietnam? The desperately rosy statements from top officials, military and civilian, in Washington; the grim, earthy statements from US officers and troops in the field in Vietnam; the eroding public support at home; the growth of the famed "credibility gap" between what the government claimed and what was increasingly obvious to all; the first hints of changing minds and mounting opposition to the war in Congress and the first calls for timetables for withdrawal?

Excuse me if I'm confused, but didn't the men (and one key woman) of the Bush administration pride themselves in having learned "the lessons of Vietnam" (which, as it happens, they played like an opposites game until the pressure began to build when they suddenly began acting and sounding just like Vietnam clones)? Isn't our president the very son of the man who, when himself president and involved in another war in the Gulf, claimed exuberantly, "By God, we've kicked the Vietnam syndrome once and for all." Well, here's a news flash then. In Washington today, they're mainlining Vietnam.

Maybe we should really be examining the later history of the Vietnam War for hints of what to expect next. Certainly, as in Vietnam, we can look forward to withdrawal strategies that don't actually involve leaving Iraq. In Vietnam, "withdrawal" involved endless departure-like maneuvers that only intensified the war - bombing "pauses" that led to fiercer bombing campaigns, negotiation offers never meant to be taken up. Or how about ever more intense and fear-inducing discussions of the bloodbaths to come in Iraq, should we ever leave?

For years in Vietnam, the bloodbath that was Vietnam was partly supplanted by a "bloodbath" the enemy was certain to commence as soon as the United States withdrew. This future bloodbath of the imagination appeared in innumerable official speeches and accounts as an explanation for why the United States couldn't consider leaving. In public discourse, this not-yet-atrocity often superseded the only real bloodbath and was an obsessive focus of attention even for some of the war's opponents. In the meantime, the bloodbath that was Vietnam continued week after week, month after month, year after year in all its gore. Or how about the development of right-wing theories that the war in Iraq was won on the battlefield but lost on the home front; that, as in Vietnam, we were militarily victorious but betrayed by a weak American public and stabbed in the back by the liberal media? Watch for all of these, they're soon to come to your TV set.

Oh, and speaking about Vietnam-era parallels, how about this one: It turns out there are two different races of Iraqis. There are their Iraqis - jihadis, Ba'athist bitter-enders, terrorists, Sunni fanatics and even, as Major General Joseph Taluto, head of the US 42nd Infantry Division, admitted the other day, "good, honest" Iraqis "offended by our presence". The thing about all of them is, without thousands of foreign military advisers, or a $5.7 billion American-financed program to train and equip their forces, or endless time to get up to speed, they take their rocket-propelled grenades, their improvised explosive devices, their mortars, their bomb-laden cars, and they fight. Regularly, fiercely, often well and no less often to the death. They aren't known for running away, except in the way that guerrillas, faced with overwhelming force, disband and slip off to fight another day.

American military men, whatever they call these insurgents, have a sneaking respect for them. You can hear it in many of the reports from Iraq. They are - a typical word used by military officers there - "resilient". No matter what we throw at them, they come back again. All on their own they develop sophisticated new tactics. Facing terrible odds, when it comes to firepower, they are clever, dangerous, resourceful opponents. The adjectives, even when they go with labels like "terrorists", are strangely respectful.

Then there's this other race of Iraqis, as if from another planet - our Iraqis, the ones who scatter "like cockroaches". They are, as several recent articles on the desperately disappointing experience of training an Iraqi army reveal, not resilient, not resourceful, not up to snuff, not willing to fight, all too ready to flee, and, in the eyes of American military men on the scene, frustrating, cowardly, child-like, and contemptible.

Compare that, for instance, to the following comment on the enemy: "The ability of the [insurgents] to rebuild their units and to make good their losses is one of the mysteries of this guerrilla war ... Not only do [their] units have the recuperative powers of the phoenix, but they have an amazing ability to maintain morale." Oh sorry, that wasn't Iraq at all. That was actually General Maxwell Taylor, American ambassador to South Vietnam, in November 1964.

Let's face it. This is deja vu all over again. In Vietnam, their Vietnamese regularly proved so much more admirable - in the eyes of American military officers than ours. America's Vietnamese often seemed like the sorts of thugs white adventurers in Hollywood films had once defeated single-handedly. They were corrupt, cowardly, greedy and rapacious in relation to their own people, and regularly amazingly unwilling to fight their own war. The enemy, on the other hand, often seemed like "our kind of people". They were courageous, disciplined, willing to endure terrible hardships, and capable of mobilizing genuine support among other Vietnamese.

Major Charles Beckwith, the chief American adviser to the Special Forces camp at Plei Me, was not atypical in his reported comment after a siege of the camp was broken, "I'd give anything to have two hundred VC [Vietcong] under my command. They're the finest, most dedicated soldiers I've ever seen ... I'd rather not comment on the performance of my Vietnamese forces."