Surely there are few sadder phenomena in postwar American history than the deterioration, both physical and psychological, of New York City. At war's end it was, as Roger Starr writes in this fine book, "certainly the world's strongest surviving city," one not merely unscathed by combat but possessed of energy, ebullience, self-assurance and confidence; to residents and outsiders alike, its prospects seemed limitless. Yet now, only four decades later, it is a city in decline; its infrastructure is wasting away, its manufacturing base has shrunk, its crime is pervasive, its gap between rich and poor is wider than ever, its housing is chaotic.

How it got that way is Starr's subject, in a pungent little book that is distinguished by bluntness and a willingness to face unpleasant truths. Starr, a former city housing commissioner and businessman who now writes editorials for The New York Times, loves his city and is dismayed by its decay, but his own feelings do not prevent him from looking at matters with a cool eye. What he sees will seem pretty only to connoisseurs of self-destruction and hubris.

Starr begins with Lincoln's Birthday 1946, when the incumbent mayor, William O'Dwyer, ordered the city to suspend its ordinary business in response to a strike by tugboat workers -- an order that was cheerfully obeyed by the citizenry and that helped bring the strikers to terms. This, Starr argues, was a high moment in the city's history, a demonstration of urban spirit and manners that has subsequently gone virtually unmatched; since then, Starr quite accurately writes, there has been a "decline in New York's civility, the custom of treating other citizens with the minimal courtesy to which shared status as New Yorkers entitles them."

But basic human decency is scarcely the only area in which New York has deteriorated. One by one, Starr examines those aspects of city life in which New York was healthy in 1946 and is ailing in 1985: its harbor, its subways and mass transit, its manufacturing economy, its schools, its housing supply, its lawfulness, its hospitals and sanitation, its local government, its cultural life. In none of these areas can Starr now find cause for optimism; on the evidence, in none of them would he be justified in doing so.

Starr's analysis of the subway system is typical of his careful, unsentimental approach. The subway was in substantial measure responsible for creating New York as it existed 40 years ago: it bound the city together, made travel from one part of the city to another speedy and cheap (and safe), brought in the workers who made Wall Street and midtown thrive. But political commitments to unrealistically underpriced fares eroded its financial base, and left the Mass Transit Authority without the funds for repairs and modernization. Ridership is now sharply down, because people no longer can trust the subways to run reliably, because they are afraid of widespread and random crime, because there are fewer manufacturing jobs in the city to which to commute. The result is that subway revenues are down as well, and there is an increasingly likely prospect "that the entire system will come, bit by bit, to a stop."

Starr is every bit as forthright in his examination of rent control, which he quite properly identifies as a critical influence on New York's inability to construct sufficient housing or to maintain its "once-good apartment houses and apartment-house neighborhoods"; of conflicting attitudes toward crime, which demand stern enforcement of laws on the one hand and "humane" treatment of prisoners on the other; of the balkanization of the city school system into a loose federation of warring districts; of the rise in dependency and the subsequent institutionalization of the welfare culture.

On this last subject, as on several others, Starr argues that the city's liberal elite is largely at fault: " . . . a society that fails to draw a clear line between the ethic of dependency and the ethic of self-support is doomed to an increase -- a continuing increase -- of dependency," he writes. "A society that rewards young women for producing illegitimate children is a society that has failed to draw a line clearly at a vital juncture. Such a line cannot be drawn by government, nor should it. But a society whose elites, black and white, fail to understand that a line should be drawn between moral and immoral conduct is failing in its duty to the dependent and to their offspring, generation after generation."

This is not a view likely to win Starr much popularity among the fashionable of Manhattan, who are too busy in the pursuit of self-gratification to contemplate the many ways in which they have permitted their city to crumble away beneath them. But there is much truth to his contention that New York is the victim of nothing so much as its own hubris, and that its failures of self-discipline have the potential to be fatal. If that indeed proves to be the case it will be lamentable, but it will be no one's fault except New York's.