TO ME ONE of the most moving passages of Tender Is the Night is F. Scott Fitzgerald's soliloquy delivered atop the abandoned trenches of the old Somme battlefield. He says, prophetically:

"This Western-front business couldn't be done again, not for a long time. . . . This took religion and years of plenty and tremendous sureties and the exact relation that existed between the classes. . . . You had to have a whole-souled sentimental equipment going back further than you could remember. You had to remember Christmas . . . and going to the Derby and your grandfather's whiskers."

As far as Britain was concerned, the "sureties" Fitzgerald was talking about were those inherited from the long Victorian era, and they help explain why, alone of the major combatants in World War I, the British Army never mutinied, revolted or broke. Looking back from the anarchy of the late 20th century, the memory of "grandfather's whiskers" now provokes a steadily growing nostalgia, even to the extent of admiring Victorian architecture. For all its inherent brutality and insensitivity, at times the century of Pax Britannica actually begins to look as if it may have achieved a better life (or at least less suffering) for more people than the past half-century of Pax Russo-Americana. I write, of course, as a Brit.

The British Army left behind by the Victorian world was, in the words of Byron Farwell's delightful and extraordinarily well-informed book, "a peculiar little army." When Prussia mustered 888,000 men for its war with France in 1870, and even Italy had 629,000 soldiers, the British army numbered only 186,000 Bismarck once commented that if it ever landed on Prussian soil he would send a policeman to arrest it. Alone among the European nations it had no general staff; General Sir Garnet Wolseley, Gilbert & Sullivan's model of the "Modern Major-General" and probably the brightest of them all, couldn't spell and thought the use of trenches in the American Civil War was bad for morale. It was an army raised on the cheap; officers could only get commissions if supported by private incomes, while Kipling's "Tommy Atkins" was appallingly paid and, after a lifetime of devoted service, would be discarded in penury. He joined because it offered camaraderie, but above all security -- which applied particularly to the deprived slum dwellers, many of whom were incapable of passing the rudimentary physicals.

It was "peculiar" also in its mass of eccentricities and bizarre regimental traditions. Farwell shows here a depth of knowledge, and almost of affection, that few outsiders could be expected to have. He knows for instance that the Coldstream Guards, although the oldest regiment in the British Army and bearing the proud motto of "Null Secundus" for "Second to None"), in fact doesn't come first in the line, because it happened to fight for Cromwell, rather than the king. Officers to the elite Brigade of Guards do not "sir" their seniors, except the colonel; they may wear headgear at breakfast, a custom considered barbarous by the "Line"; and they refer to each other with friendly contempt, the Welsh Guards still habitually being known as "the Foreign Legion." But -- like the U.S. Marines -- they were expected to fight harder and "die better" than the "lesser breeds" within the army.

Farwell also knows about the famous regimental mascots, such as the goat of the Welch Fusiliers which was accorded a military funeral with full honors when it died. Permanently in charge of it was a noncom called the "Goat-Major," one of whom was once court-martialled for "disrespect to an officer" after offering the mascot's stud services out to a local farmer. Customs died hard; as a Coldstream Guards recruit in World War II, I still remember blacking the coal with boot-polish for company inspection; later, as an ensign, even then I received only the equivalent of $1.50 a day, and it was strictly forbidden to be seen carrying a parcel or with a woman on your arm -- except for wives, financees, and "your ancient mother." The 60th Rifles, raised in North America during the Revolutionary War, still drew heroic Americans to its colors to fight for Britain in 1940, pre-Pearl Harbor.

Even after flogging was abolished (and that was not until 1879), discipline in Mr. Kipling's Army remained harsh. The gulf between officers and men was immense; the latter found their pleasures in gin, whores and gambling, while the officers spent most of their time shooting or hunting (as far as sex was concerned, Lady Wolseley once complained that the Modern Major-General had "no time for God or me"). There was the rare phenomenon of the ranker who (like Field Marshal Robertson) rose to the top; otherwise social mobility was rare, fraternization nonexistent. Yet, there was a curious interrelationship between the two, bred partly on a shared love of war (but then, by 20th-century standards, war was not all that terrible), in which "Tommy Atkins" expected (and generally found) unflinching bravery on the part of his officers. Above all officers and men were bonded by the fierce internal and regional loyalties of the regimental system, imposed on an unshakable, collective sense of arrogant self-confidence. "The Queen believed in herself, and we believed in her," they said. Towards the "lesser breeds" abroad this arrogance could be intolerable; "the wogs begin at Calais," a sergeant-major warned his men in 1914 and there are indeed still Britons who believe that today (though, curiously, perhaps more often to be found now among the isolationist left than the old Kiplingesque army diehards).

For all its bizarreness, however, this "peculiar little army" worked. Perhaps, throughout the 19th century, it did succeed in fulfilling the role for which it was designed better than the vastly more complex Western armies do today. But the bloodbath of 1914 came as a terrible shock to it; had it not been for those mysterious bonds (so well described by Farwell) that held it together, it would almost certainly have died of that shock.

My one complaint against Farwell is that, in his generosity to Mr. Kipling's Army, he ignores that -- thanks to Wellington and Waterloo -- for the best part of a century it operated in a vacuum. There was no Soviet colossus lurking in the wings. Therefore it is quite unfair to make any parallel to the performance of the U.S. army in Vietnam. When Farwell remarks that "the most technologically superior army the world has ever known has been put to flight by Asian peasants in black pyjamas," he grossly misreads modern history. My reading of recent history is that it was defeated by the long-haired campus incumbents, by the Jane Fondas and Mary McCarthys, and finally by Congress -- not by the little men in black pyjamas. One wonders how Mr. Kipling's "peculiar little army" would have fared in a war which they knew those in "Blighty" didn't want to go on fighting.