ABOUT 15 YEARS ago, the then managing editor of this newspaper put to me, out of a clear sky, a question as stunning as if he had dealt me a blow on the nape of the neck with a bludgeon.

"Wave," he asked, "do you have an American passport?" I was so flabbergasted that I Muffed the answer. I should have said: "Yes - since 1635."

A few days ago my wife asked me what was basically the same question turned around: "Why don't you apply for French naturalization?" This time the answer came automatically. "Because," I said, "my name is Root."

She put the question because Sens. Proxmire, Ribicoff and their fellows are giving Americans abroad, as a result of the new tax laws affecting them, a choice between going home, going native and going bankrupt. (How does it happen, incidentally, that the senators have presumed to take the lead in a field which, according to the Constitution of the United States, Article 1, Section 7, is the prerogative of the House?)

My wife could not of course understand the enormity of her question. Being French, it did not occur to her that there was anything dishonoring about becoming French.

Indeed, if I should adopt French nationality it would not be dishonorable; but it would be untrue. Any legal document (however effective in practice) which described me as anything but American would be a fiction. That I am American is a simple fact, bred in the blood and the bones - because my name is Root.

Let me try to explain why a Root cannot renounce his birthright, nor can the thousands of other Americans living abroad who, like myself, belong to the families which are the oldest in America, the ones who supplied the brawn, the bones and the brains which shaped American thinking and American living and created the Republic.

I once read, in some encyclopedia, a reference to the great families of America which listed a few of them - not many, 10 at the most. One of them was Root. This surprised me. It had never occurred to me to think of the Roots as a great family. A solid family, yes, a basic family, yes, a typically American family, yes. But not a great family, in the sense of being a famous family. I suspect that just now, when I raised the question of great American families, some names popped into your head. And if they did, I suspect also that they fell into one or the other of two categories (barring those of the Founding Fathers and of Abraham Lincoln, which are too obvious) - the very wealthy or politicians.

The Root family does not normally fit into either bracket. I fear we believe in Horatio Alger: Apply yourself well and diligently to your work, whatever it may be, and wealth will automatically reward you; but of course it doesn't. I suspect we are primarily interested in our work, and in performing it with due regard for professional ideals and ethics, and only secondarily in how much we are paid for it, though without going to quixotic extremes in disdain for money. We are not much interested in the exercise of politics either, having little interest in concocting laws for others to obey.

It is true, I suppose, that the most famous member of the family was a politician - Elihu Root. I met him just once, in 1929, and was struck immediately by his resemblance to my father: They could have twins. Yet their relationship was distant. I tried to trace it once in the family genealogy but gave up the attempt to pin it down, with a vague impression that they were something like sixth or seventh cousins.

The genealogy I consulted, incidentally, was not that of the Root family but of the Mack family; how it happened that we were so classified, or what the Mack family represents, I have no idea. I did learn from this work that destiny had doomed me to become a journalist, for I was a stop-press baby. The book was being printed when I was born, and the presses actually were stopped to get me in.

I have no idea either how we were linked to the Warren family, which gave the nation a chief justice and several other important citizens. I remember only, from a very distant past, my cousins Janet Warren and her sister, whose name I have forgotten - two lovely girls, tall, quietly beautifully, well bred, possessors of a serene charm - a type out of style nowadays.

They would have been of the generation after my father's cousin, Frances Warren, the subject of a family anecdote. When my father received an invitation to her wedding, he snorted: "If Frances thinks I'm going all the way to Texas to see her marry some shavetail lieutenant, she has another think coming." I told this sometime in the 1920s to the shavetail lieutnant, who in the meantime had risen to the rank of general. His name was John J. Pershing.

Having had a secretary of state in the family creates the curious delusion that one has a proprietary right to that function. Sitting in Cordell Hull's office talking to him about his recent trip to Russia (1942, perhaps?), I told myself that when I came to occupy those premises I would get rid of the rubber plant and the brass spittoon; as it happened, I never got around to it.

My meeting with the only Root who had ever been in a position to rearrange this furniture occurred because I was holding down the job of Rome correspondent for the Chicago Tribune when my illustrious relative boarded an Italian liner on his way to a meeting of jurists examining the revision of the statutes of the Permanent Court of International Justice. The Chicago Tribune cabled me to get on the ship at Naples, ride to Genoa with him and find out what it was all about.

At Naples, I checked with the American consulate to make sure that the ship was arriving on schedule and that no changes had been made in Root's plans.I fear I forgot to tell them I was a newspaperman, but in spite of this omission the name of Root procured me such fawning solicitude that if I had had no further contacts with American official-dom abroad I might still be sharing the naive delusion of Sen. Proxmire, expressed publicly not so very long ago, that the United States maintains its Foreign Service, at enormous expense to the taxpayers, solely to coddle the wealthy, bloated Americans who live abroad.

Secretary Root turned out to be friendly, unaffected, unpretentious and uninformative. He was not prepared to reveal secrets of state even to a member of the family. I had to wait like everybody else to learn that the result of the Geneva meeting would be the document known as the Root Protocol. Failing politics, we talked family. He seemed to know the Root history by heart. I gathered that he felt about its role in the life of the nation much as I do now.

The only other member of the Root family who has made any impact on the national culture, not a prominent one, was George Francis Root, a sort of surrogate of Stephen Foster. He composed, if memory serves, "Tenting Tonight on the Old Campground" and "When Johnny Comes Marching Home Again." I will not guarantee these titles, but if I have picked the wrong ones, these will at least serve to give the flavor of his work.

His middle name is endemic in our family. My father's name was Francis and it would have been mine too, as the eldest son, if the family rules had been followed when I was born (since I did not inherit the name, the younger of my two brothers became Lindsay Francis Root).

Tradition sliped a cog in my case when my great aunt, Martha Tillinghast (a Providence name) became enamored of the works of Sir Walter Scott and bestowed the name of Waverley on my unlce, Waverley Tillinghast Wonson (a Gloucester name), who passed it on to me. Though he did not bear the name of Root, Uncle Wave was a first cousin of the Root he married, and was in tune with the family in performing competently a responsible, fairly important but inconspicuous function as treasurer of the Andrew J. Lloyd Company of Boston, which dealt in fine optical instruments.

The Root family arrived in America in 1635 and, with two or three other families, founded the town of Middlefield, Mass. I have never been to Middlefield, but I have seen photographs of the Root family plot in its cemetery; we are quite impressive dead.Three centuries is a considerable stretch of time in American history, but my grandfather and grandmother, though they lived in Boston, were still spending their summers in Middlefield until they died, shortly before World War I.

My immediate relatives were, I think, typical enough of the Root family as a whole and of all the other corresponding American families who, in inconspicuous roles, kept the everyday life of the nation functioning in the American spirit, unspectacular but dependable.

My grandfather, so far as I know, was not notable beyond the somewhat limited sphere of East Douglas, Mass., where he owned the general store and a farm which permitted him to give tangible form to his kindliness (a characteristic trait of the family). Those were the days of the Great White Plague, when tuberculosis was as feared as cancer is today. My grandfather took in sufferers from the disease, providing them with the pure country air and the solid farm food which they needed for recovery.

It may be that my grandmother reached a wider audience than he did. I remember that she occasionally addressed women's clubs, though on what subject I don't know. It would have been a generation too early for women's suffrage. This became my mother's activity, leading me, in my Boy Scout uniform, to beat the drum for rallies, and winning me the only pledge I have ever received for a vote for the presidency, from Dr. Anna Howard Shaw, whom I had driven at break-neck speed from one meeting in Brockton to another in Fall River.

My grandmother was born Amanda Lane, which is why one of my sisters is Martha Lane and my daughter Diane Lane; we have a sense of continuity. The Lanes were a family of the same type as the Roots. When I entered Tufts I found a distant relative of my grandmother installed there as professor of geology, Alfred Church Lane. He won national notoriety in 1936 by resigning his chair rather than take the loyalty oath imposed on teachers in that year by the state of Massachusetts - not that he was opposed to the principle that the right to teach should be dependent upon allegiance to any political system, however praiseworthy. A Root would have acted no differently.

(Other non-Roots but near-Roots included another Tillinghast, first name forgotten, who was for many years secretary or treasurer, I have forgotten which, of the state of Massachusetts, and further back in time, an ancestor of my mother, John Rowe, who in 1748 was responsible for the hanging in the legislative chamber of Massachusetts of the replica of a cod, the backbone of the local economy; it is tucked away still, I have heard, somewhere in the State House, preciously preserved despite the description of it as "the figure of a codfish of natural size made of wood and in bad taste.")

My grandfather, widowed once, married twice. His son by his first wife had been gratified by his mother, a devoted reader of the Bible, with a choice example of the old-fashioned New England scriptural names which no one would dream of inflicting upon helpless infants nowadays - Azariah (Uncle Azzy to me).

Azariah Smith Root became professor of bibliography at Oberlin, the college librarian and was a founder of the New York Library School. His daughter Marion was curator of foreign language books at the New York Public Library until her retirement; his son, Francis, became professor of etymology at Johns Hopkins. (Professors seem to run in our family; Elihu Root's father was a professor at Hamilton.)

My father, the son of the second marriage, was an electrical engineer, an honorable if anonymous pursuit, in which he exercised a good deal of responsibility as power engineer of the Fall River Electric Light and Power Company at a time when Fall River was the largest cotton manufacturing city in the world, measured by number of spindles.

He was unknown to history but known to his profession as a frequent contributor to the journal of the American Association of Mechanical Engineers, and perhaps deserved to be known more generally also, for he was instrumental in developing the block-signalization system used today on all the world's railroads to insure safety. He let others take out the patents. A typical Root.

His sister, my Aunt Martha, was a typical Root too, and a typical New Englander as well. (Martha is a family name also. There were times of family reunions in my youth when there were five Marthas in the same house at the same time. Calling the same from one room to another plunged the place into complete confusion. There would be three Francises at those gatherings too, and I doubt if it has ever possible anywhere else to receive two answers from a cry of "Waverly!")

Aunt Martha was the typical tall, spare, large-boned New England women, a trifle rough-hewn as to visage, like a wooden Gothic statue, but she radiated so much charm that she entranced everyone, and she did not know how to be otherwise than kind. She did nothing in particular except to preside efficiently and unobtrusively over a remarkably pleasant home, and participate actively in the life of her neighborhood, informal and easy-going, which refrained from becoming institutionalized.

Some of the women of her community (first Roslindale, then Roxbury, Mass.) met together periodically, at one home or another, to exchange books and discuss them, but they carefully refrained from organizing themselves into a book club, and others had similar get-togethers to talk gardening, but they kept their contacts informal, and never set up a gardening club. My aunt was an expert on roses.

It would be difficult to be more thoroughly New England than I am. My political persuasion is mugwump; my political philosophy that of being "agin the government." What could be more purely New England? (The Constitution is "agin the government" too: Consider the first 10 amendments, the Bill of Rights, of which the first begins flatly, "Congress shall make no law," while the other nine could be rephrased to start in the same fashion, for all of them are concerned with restricting the powers of government, including legislators. I call its implications to the attention of Sens. Proxmire and Ribicoff, and indeed of all the members of Congress, who seem inclined to forget that the document which gave them their powers did so with great distrust.)

My education was typical New England, too.I went to a family college, Tufts, attended also by my father, my mother, my aunt and my sister. Like most private New England colleges, Tufts had started out as a theological college. The denomination was Unitarian, thoroughly New England.

With a background like that, how could I possibly consider renouncing my American nationality?

But how do I avoid it? American nationality is being converted into a luxury beyond my means by the new tax law, about which a good deal has been written, much of it beside the point, and a new Franco-American tax treaty, about which little has been written.

Resident in France, I have for a decade or more been paying more taxes on my revenue than a French citizen would pay on the same income. The United States is now demanding that I pay more taxes on my revenue than would be paid by an American at home on the same income. Both countries have changed their laws simultaneously. France claims the right to tax not only my income in France, but also my income in the United States; the United States claims the right to tax not only my income in the United States, but also my income in France.

This situation makes plausible the description of the new tax treaty, now awaiting ratification, as an agreement intended to prevent double taxation of French or American citizens. This description is familiar; I have heard it many times during the 52 years when, as a journalist, I have been professionally involved in extracting the meaning from the bureaucratic doubletalk employed by all governments - repeat, all governments - to deceive their citizens about what is being done to them.

It is my observation that governments couldn't care less if their citizens are taxed doubly, unless their resentment is likely to be expressed in their votes. The object in making such agreements is not to make sure that nobody shall be taxed twice, but that everybody shall be taxed at least once.

The fear is that somebody, by living between two countries, might escape the attention of the tax collectors in both of them and pay taxes to neither. A standard feature of such treaties is a provision for the exchange of information - in other words, each government agrees to tattle on its own citizens to the other government.

I am unable to interpret the real meaning of the Franco-American tax treaty, for it seems incomprehensible. When the International Herald Tribune first reported its conclusion, it quoted a tax lawyer who said he had read its 20 times and was still unable to figure out what it meant. Who am I to rush in where tax lawyers fear to tread?

I do note, however, that the new treaty affects me personally in at least two sectors.

First, it disinherits my wife. The will I filed several years ago with a probate court in Vermont becomes invalid, for the United States is agreeing that its citizens living in France shall be subject to French inheritance laws; French law discriminates against wives in the matter of inheritance.

Second, the treaty divides the power of taxation between the two countries in such a way that any tax break allowed by one country is annulled by the other. France in this matter shows a little more forebearance than the United States. It simply taxes any income left exempt by the United States; but income exempted by France is confiscated totally by the United States.

There is only one way out of this intolerable tax situation - to live in the country of your official nationality; you are then accountable to only one country. My wife points out that I can achieve this by becoming French; but I can also achieve it by returning to the United States.

Why don't I? A good many Americans have already done so since the passage of the new tax law, leaving their jobs with American companies to Europeans.

I have on several occasions considered returning to the United States. I even know where I would like to live - Chelsea, Vt., where I once owned 1/4,206,787th of the national territory. But I can't.

First: I haven't the money to move. There are other Americans resident abroad who are in the same position. This renders all other reasons superfluous, and I could stop here if I were describing only my own situation; but I am offering myself as a sample of all Americans abroad, so let me offer just two more from what could be a longer list.

Second: Presence in France is part of my stock in trade. Americans living abroad may have diverse reasons for being unable to pull up stakes, abandon long-established situations and return home to start again, perhaps at an advanced age, from zero.

In my case, one of my assets is the knowledge acquired from long residence in France, which will become outdated if I leave. I think it's pertinent to point out that this knowledge has been put at the service of the American government on at least three occasions when organisms of that government have asked my cooperation, and have of course had it, on major matters. I am not speaking of minor services, such as broadcasting to occupied France during the war, which many other persons did also, but of matters concerning high policy, when I was told that I was the only person to whom the government could usefully turn. It goes against the grain to claim any merit for this, but I suppose I must add, to make this report complete, that all of these services were performed without pay.

Third: Family ties hold me to France; and this again is true of many Americans living abroad. My wife is French. She is as deeply attached to her country as I am to mine, and in a geographical sense, more so. The French are less mobile than we are. My wife's family has property in the Dordogne; they have held it since about 1550, 100 years longer than the Roots have been in America. Her mother, who is 90, lives on it today. Her son, who is 30, and her grandson, who is 3, live as we do in Paris. My wife is over 60 and speaks virtually no English. How can I take her, at that age, away from her own country and her own relatives, and ask her to begin a new and, for her, strange life? The answer is that I can't.

It may be that Sens. Proxmire and Ribicoff, the chief instigators of the new tax law, are among that not inconsiderable number of Americans who think there is something immoral, or at least unpatriotic, about Americans who live in any other country than their own.

This view is held by the Soviet Union, and we lecture Moscow about it, in the name of the rights of man and of the Helsinki Pact. The Helsinki Pact does indeed hold that a country should be a home for its citizens, not a prison, and that everyone should be free to live where he likes. If there were anyone with a sense of humor in the Kremlin, which seems improbable, I could imagine him composing now a tongue-in-check declaration berating the United States for confining its citizens to their home territory by means of fiscal measures.

Must I, because of fiscal measures, allow Sens. Proxmire and Ribicoff to deprive me of the nationality I have honored as my birthright since 1635?

I'm damned if I will. CAPTION: Picture, Passport, By Saul Lambert for The Washington Post