One cannot but admire the nation or city that continues to dispatch troops in an unwinnable, though righteous, war, and so it was with affection we set off the other day to visit New York City's premier graffiti cops, Hickey and Ski.

They were ensconced in their shabby headquarters in the Bronx, but it was clear, before even crossing the threshold, that they were involved in a losing battle. En route, graffiti obliterated the subway cars so that one could not even see out the windows. Graffiti marked the mailboxes. Graffiti marked the back of the very offices in which Hickey and Ski sat.

One thought, in fact, that it was a good thing the blue sky over the Bronx was too high to hit with a can of Rustoleum red, otherwise, it, too, would be covered with "CRASH" or "1BX."

That view was reinforced by a chat with the officers, two of four New York graffiti specialists on a 30-man vandalism squad.

"The city just spent $15 million on ribbon razor wires, putting them around the yards to fence out the nighttime vandals . Looks like the Maginot Line," said Kevin Hickey, 38. "These kids have better wire cutters than the city. They go into the stores and liberate them and just cut through the wire."

"We find this big hole in the fence the other day," said Conrad Lesnewski, the Ski. "And then, on the No. 6 line, this kid writes, 'Don't fence me in.' And another one, 'I eat razor blades.' "

Graffiti is a serious problem for the city, particularly of late, with subway ridership the lowest it's been since 1917. The destruction is put at between $5 million and $10 million a year.

As frequently as the politicians announce the clean-ups of Times Square -- and with about as much success -- they launch attacks on graffiti. Battle plans change with the season. They force captured graffiti POWs to scrub the cars clean. They try a $100,000 public relations campaign that calls for kids to "make your mark in society, not on society." They make the kid -- if he's over 16 -- pay maybe a $50 fine or, rarely, spend a little time in jail.

Or maybe they spend $709,000 painting 409 trains white with a new Teflon-style paint -- a technique that turns off graffiti vandals in the same way a tightly stretched canvas, washed up on the beach, would turn off the impoverished French post-impressionist Gauguin.

One hears, nonetheless, that this paint was introduced because graffiti can be washed right off.

Ski laughs.

"Sure," he says. "Ya believe in Christmas? Ya believe in the tooth fairy?"

This is battle humor, bitter and cynical, with none of the optimism expressed in the communiques dispatched from the mayor's office downtown.

Hickey and Ski are veterans of the graffiti wars, with 10 years in the trenches. They're known to the other units and known to the kids they chase. How well known became clear in a long ago battle of Christmas '75, when a graffiti-covered train rushed by Yankee Stadium.

It was a major piece -- in graffiti lingo, a "masterpiece" -- stretching the length of the car. It had Santa and his reindeer and Frosty the Snowman and down on the bottom there was an inscription.

"Dedicated," it said, "to Hickey and Ski."

More recently, Hickey and Ski were invited to an opening at Graffiti Gallery in Greenwich Village. Ski, who attended, knew the artists well, having arrested most of them.

In a war, particularly a long war, there develops a certain affection between the parties.

Hickey and Ski expect a certain gentlemanly behavior from the minor felons who are their prey, often calling them at home and giving them the option of turning themselves in, since, after all, Hickey and Ski know how and where to find them.

They consider it an affront to have to actually give chase to graffiti criminals, their old bones having grown weary, and, anyway, they have a reputation to protect.

"C'mere you little mutt!" Hickey screams, "It's us!"

They know what motivates the felon and causes him to stand on the school rooftop and wait hours for the train with his name to go by: the drive, in the words of the kids, "to get fame."

They say that no matter the artist, the first words upon surrender are the same: "I just quit."

Hickey and Ski are also connoisseurs of the work.

At the 180th Street subway stop behind their offices, they pause on the platform and point out works past and present, with a nod to "COMET" and "BLADE," written on the back of their offices.

"COMET," said Ski, "he's graduated to bigger things now, homicides, robberies. And you see the way CAP went over it, there? That's something you never used to see, you see now more and more, when there's a war. We get a lot of stabbings and shootings over that, now. CAP gets away with it because he's a big husky kid. Also, he carries a sawed-off shotgun."

Ski points out "DUST," on a telephone booth.

"You see that?" he said. "That's a half-crippled guy, about 30, who works on crutches. On crutches! Used to stand on the roof and watch his name go by. You know the first thing he said to me when I arrested him?

" 'I quit.' "