"You have, ladies and gentlemen, to give this much to the Luftwaffe," said the Prince of Wales. "When it knocked down our buildings, it didn't replace them with anything more offensive than rubble. We did that."

With that astounding comparison of the contemporary London cityscape to the Battle of Britain did Prince Charles, heir to the throne, inaugurate six years ago his astonishing campaign against modern architecture and modern planning.

The occasion was the 150th anniversary of the Royal Institute of British Architects, one of those august, ceremonial events where one wouldn't have expected more than the usual elegant bromides from a royal guest long ago thought to have been stripped of authority to say or do anything of real consequence.

Predictably, the reaction was resentful. "In 1984, at Hampton Court, the Prince of Wales came to dinner," recounts Maxwell Hutchinson, current RIBA president. "Too late, his hosts -- the RIBA -- realized they were the main course." Thus began the so-called "Great Debate" on architecture in England.

Today Prince Charles brings his charisma, his gift for the stinging turn of phrase and his architectural crusade to this distant shore. In the afternoon he will preside over the official opening of an exhibition, "Sir Christopher Wren and the Legacy of St. Paul's Cathedral," at the Octagon Museum. In the evening at the National Building Museum he will deliver the principal address for the annual awards banquet of the American Institute of Architects.

Naturally, there's some anxiety about a repeat performance of "the royal blitzkrieg," as it's been called. On Sunday Stanley Tigerman, one of the participants in a symposium of notable American architects here on the subject of the prince, gave mean voice to that concern, wondering pointedly whether or not "the AIA is validating the views of a foreign national."

The entertainment value of the prince's appearance obviously is great. Its educational worth remains to be seen. Since that initial RIBA shocker Charles has delivered major speeches on the subjects of architecture and planning at the rate of about one per year, has narrated his own hour-long television special and authored a handsome book based on it, "A Vision of Britain." But the exchange between the prince and his critics has seemed no more than a noisy schoolroom brawl in which the charming, sincere, quotable and deceptively soft-spoken king-to-be has given as well as he gets.

He has compared a proposed tower by Mies van der Rohe to "yet another giant glass stump, better suited to downtown Chicago than to the city of London." A design for an extension of the National Gallery in London was, he said, "like a monstrous carbuncle on the face of a much-loved friend." Of a convention center to be constructed in Birmingham, he recalled, "Choosing my words to be as inoffensive as possible, I said I thought it was an unmitigated disaster."

In return, his critics have accused him, among other sins, of superficiality, backwardness and blatant authoritarianism. "The debate over architecture has broadened considerably in the wake of the prince's comments; it's now a mile wide and an inch deep," wrote Hutchinson. "This guy is a kind of Estee Lauder salesman, putting a kind of makeup over all the world's problems," chimed in American architect Eric Owen Moss last Sunday.

With the prince's constant prodding, said noted British high-tech architect Richard Rogers, "modern architecture is in danger of being obliterated by an indiscriminate wave of nostalgia." Sherban Cantacuzino, secretary of the Royal Fine Arts Commission, opined that "by allying himself with the forces of reaction the prince prompts a comparison with the proscriptions typical of totalitarian regimes."

It's not so much that the truth is more complicated, or that it may be located somewhere in between -- though both points are obvious enough -- as that the debate is a non-debate. On the one side you have His Royal Highness and his conservative architecture advisers, and on the other the modern architectural establishment. Each party occupies an entrenched position; each is equally unfair to the other; each fights without compromise for the ideological rights to the future.

Charles, however, has maintained the initiative by the very consistency of his attack and by smartly exploiting his command of attention from the media. Architectural commentator Charles Jencks, for one, believes this relationship between the press and the royal family "in the information world of today" to be the basis of a new stage in the evolution of England's constitutional monarchy -- the "New Wave Monarchy," he calls it.

There are three main thrusts to Prince Charles's thoughts on architecture and urbanism. The first is his adamant anti-modernism, exemplified in the Luftwaffe statement. In this he is a late -- but very prominent -- convert to a revolt against modernist orthodoxy that began in outrage three decades ago with the publication of Jane Jacobs's "Death and Life of Great American Cities."

The second is his scathing contempt for what he has called, among other things, "the over-numerous shackles of bureaucracy and the all-pervading atmosphere of 'the professionals' knowing what is best for you." In this the "populist prince," many believe, was energized by a sincere sympathy for the living conditions of the poor in England's old inner cities and postwar housing. In appointing himself to be England's "unofficial ombudsman," in Jencks's characterization, he has shrewdly utilized the position of the monarchy outside of -- and above -- the daily give-and-take of conventional politics.

The third, trickiest part of the prince's campaign was initiated in a 1987 speech, in which he suggested that it was time to establish "a few sensible rules" governing development in town and city. These evolved into the "Ten Principles," spelled out in "A Vision of Britain" (see box), which understandably were labeled the "Ten Commandments" by opponents and sympathizers alike.

But if these principles were potentially the most productive of the prince's gambits -- because they attempt to encompass what he likes, as well as what he all too clearly does not -- he has made rather a mess of it. They make up a very nice wish list, although, other than including a few of his pet peeves -- sodium vapor lights, for instance -- they're fairly generalized. "They read a little bit like Design 101, what every architect should know, put in the back of his mind and then get on to the more important thing, and that is making the process work," observed American architect Arne Bystrom, aptly, on Sunday.

Still, it's not as if one can't tell where the prince is coming from. With the sort of goodwill obviously lacking among his hidebound opponents -- and by cribbing some from the codes of American architects Andres Duany and Elizabeth Plater-Zyberk or, more to the point, from Christopher Alexander's superb treatise, "A Pattern Language" -- one could piece together from the prince's hints a reasonably specific, useful set of design guidelines for urban, suburban and rural neighborhoods.

To the prince's great credit, he recognizes above all that vital neighborhoods are essential to the long-term well-being of cities and, indeed, to the global ecology; he knows that such neighborhoods, though interdependent, must be visually definable and relatively self-contained; and he stipulates most importantly that they be based where possible on existing patterns of lot sizes, streets, public spaces and the like. He endorses preservation, contextualism and regionalism, perhaps the three most important conceptual antidotes to demonstrable ill effects of modern planning worldwide.

This is a sensible stance, a humanist stance, even though it still appears to be anathema to the planning and architectural establishments in England (or so the prince would have us believe). But he mucks it up more than somewhat. Partly this appears to be a matter of royal predilection for a well-ordered, hierarchical society -- and pretty much a rural society, it would seem.

For all of his demonstrated sensitivity to the plight of the urban poor, Prince Charles cannot help but be snootily nostalgic for the countryside -- the first and last views on his television program show the prince looking wistfully at the English countryside from the window of his speeding private train. Not surprisingly, when explaining the first of his principles, "The Place," he writes almost exclusively about the landscape. This is fine -- protecting the landscape is important in this age of sprawl -- but it's excessive too. The word he lingers on, rather than "neighborhood" or "community," is "village."

The prince's chief intellectual mistake, however, is to confuse matters of architectural style with those of substance. In this he is not alone: Duany and Plater-Zyberk do it in their new resort town of Seaside, Fla., which Charles admires enough to feature in his show and book; Leon Krier, one of the prince's advisers, does it in his otherwise exemplary visual essays on cities; Alexander does it too. He could have written the prince's Principle No. 6, "Materials," which comes close to outlawing all of the products of 20th-century industry.

Prince Charles's preferred style, like Krier's, is one of refinement, harmony, ornament and proper proportion -- classic revival architecture, in sum. I have nothing against the classic revival -- it has come and gone in waves through the history of Western civilization and is one of America's proud heritages too. One of Washington's, in point of fact, something the prince cannot have failed to notice. (In several ways central Washington would seem to fit the prince's ideal of a modern city: It's classical, it's low and it provides magnificent unobstructed views of primary public monuments.)

But it is one thing to condone the style or even to love it and quite another to prescribe it almost exclusively as the appropriate dressing for architecture late in our century. (The prince allows for Gothic and other revival styles, but far from wholeheartedly.) It's a silly proposition, on its face, as is its antithesis, his enthusiastic repudiation of modern architecture very nearly in its entirety.

Perhaps the big argument here -- certainly it is one of my chief disagreements with the prince's views -- is the about the nature of cities, what makes them tick, excite, grow, thrive. Local character is desirable, of course, and has been pushed aside in too many places, but such character does not at all preclude stylistic diversity, cacophony, sharp contrasts. It's the complex underlying patterns that count most, as the prince himself has strongly implied.

If Charles's views are narrowly focused, so are those of the other side. Wounded howls are understandable -- making modern architects and hence, their architectural style, bear the brunt of blame for modern planning's faults is another of the prince's confusions, though he catches himself at it now and then. But Maxwell Hutchinson's book, "The Prince of Wales: Right or Wrong? An Architect Replies," ends with a dizzying call to modernist arms for the end of the 20th century, as if nary a mistake had been made since 1945, except maybe a little bobble here and there with some badly reinforced concrete.

It would be tempting to think that in a conflict such as this the Hegelian dialectic somehow would prevail -- and it may yet produce a new, enlightened synthesis of technology and sound urban precedent, of the future and the past. But not, apparently, any time soon.