Objectively it is nothing, a row of polished black granite slabs, cut into a gentle slope. If you approach it from the northern side, you cannot even see it. But the emotional impact, even for a foreigner, is overwhelming. So rare in America, understatement prevails. An ambiguous, terrible war, where so much individual sacrifice achieved so little, has its perfect monument. Or rather, it did.
Tomorrow is Veterans' Day, and another Vietnam memorial is due formally to be dedicated. In fact it is not the first unnecessary addition to the site. Nine years ago, they unveiled a bronze statue by the sculptor Frederick Hart, in obeisance to the Reagan-era belief that the country must no longer hang its head in unmitigated shame at what happened in Vietnam.
It consists of three infantrymen in battle. One clearly is white, another is black, while the third might well be Hispanic. Elsewhere, it would be a decent if unremarkable work, By comparison with the wall, however, it is trivial. What is more, it fails to include a woman. That omission is now being put right.
So what is wrong with a monument to a war's undoubted heroines? The answer is nothing - were it any other war, or any other place. Arguably, the bravery of the women who served in Vietnam is indeed under-represented. They numbered 10,000, many of them frontline nurses exposed to every horror of the fighting. Of the 57,692 individual names carved into the wall, of those who died in Vietnam between 1959 and 1975, only eight belong to women.
Alas, as Hart's statue before it, the newcomer merely clutters the mind as well as the site. A field nurse cradles a wounded soldier in her arms; behind her another nurse kneels, holding the soldier's helmet in her hand. A third scans the sky for the arrival of an evacuation helicopter. Plainly, the composition is inspired by the Pieta. But Glenna Goodacre, the New Mexico sculptor from whom the project's organisers commissioned the work, is no Michelangelo. The work comes across as an American version of socialist realism, or as the Washington Post wrote last week, 'like an awkward still from M*A*S*H'.
Preparations for the ceremony were already complete when I paid a visit to the fenced-off site last Sunday. The memorial itself is covered, wrapped in what seems to be a giant red, white and blue tricolour. Only outside, do you sense the tragic essence of Vietnam, of ordinary lives ensnared and often destroyed by a misguided national cause. That raw afternoon a bunch of red roses, stuffed into a crumpled beige envelope, had been propped against the fence. On it was scrawled, 'Your nursing skills and compassion kept my name off the wall. John.'
Why is that when it comes to remembering wars, America seems compelled to excess? The same has long since been evident on the battlefields of the Civil War, those testaments to a country's fear of losing contact with its past. Hardly one of them is not littered with cannons, statues and sundry regimental obelisks. Take for instance Gettysburg. Only the haunting beauty of the farm country of southern Pennsylvania, and the sheer historical importance of what happened there during the first days of July 1863, have saved the place from becoming a giant theme park.
The risk now is that the western end of Washington's Mall may be going that very way. Already the surrounds of the Vietnam shrine can resemble a bazaar of the bizarre. There are fast-food stands, and stalls plying the inevitable T- shirts, while simultaneously pressing the despairing cause of the 2,000-plus Americans listed as missing in action.
And more is to come. A minute's walk away, you notice another bulldozed site. A memorial to veterans of the Korean war is under construction. Unlike Vietnam, Korea indisputably was a 'good' war. Thus is moral equivalence established, thus is history subtly rewritten by means of monuments, and the uniquely powerful statement of the wall diminished. So it was in 1984 with the Hart statue. And so it is with the one to be unveiled tomorrow.