The Defense Department directory fails to list the Navy's Bring Back the Battleship Office, but it's surely there in the Pentagon, probably on the long-vacated premises of the Army's defunct Bring Back the Cavalry Office.

It's been years, of coarse, since there's been talk of returning the horse to the front lines but that's because careful studies of two world wars and dozens of little ones finally persuaded Army scholars that equine technology had exhausted its military potential. During this period, the battleship -- as an ocean-bottom census will confirm -- also reached the end of the line in military worth, and, without exception, all navies after World War II, were eventually directional to scrap or mummify the few surviving vessels.

However, the decision to leave any afloat, though mothballed, was a major mistake in military politics, because there they were to feed the hallucinations of the disposed ruling class of the naval service -- the oldtime battleship admirals.

Like roylist emigres monomaniacally focusing on the restoration of their long-toppled monarch, these admirals and their spiritual descendants have never deviated from the goal of reviving the battleship. To a limited extent, they succeeded during the Korean War and, briefly, during the Vietnam War, when the World War II battleship New Jersey was recommissioned and dispatched to fire at faraway -- possibly non-existent -- targets on hostile coastlines. Those were great days for the oldtime Navy, though the same weight of metal and explosives could have been delivered at considerably less cost, and with a lot more flexibility, by airplanes.

But that's neither here nor there for the battleship revivalists, whose latest ploy, now well advanced is to resuscitate four of the moth-balled 45,000-ton survivors for conversion into haulers of cruise missiles and short-takeoff aircraft.

This willingness to use the venerable ships as; platforms for airborne weapons suggests a desperation move by the now-dwindling ranks of battleship aficionados, because it was mainly the aircraft carrier that produced the downfall of the centuries-old, carefully maintained naval culture that reached its peak aboard the battleship. Manned by a crew of thousands, with nothing to do but paint and polish and ocassionally engage in target practice, the spacious battleship was an ideal platform for naval ritual and spectacle. And that cannot be said of something as busy, dangerous, dirty and noisy as the floating airstrips and maintenance shops known as aircraft carriers.

But even with the best of maritime embalming, those 35-year-old ships are slowly deteriorating -- which, for the battleship crowd, means that revival for any purpose is preferable to storage.

As recently approved by the House Armed Services Committee, the back-to-the-battleship movement is to commence with the recommissioning of the old New Jersey as a cruise-missile carrier armed for self-defense with guided missiles. The argument for doing this is that the giant ship can carry vast numbers of both these long range and close-in weapons, that its thick armor provides great protection against attackers and that this is a thrifty way for the Navy to handle its share of the cruise-missile force. The cost, inevitably, is said to be considerably less than doing it any other way.

What's left out of the arguments in behalf of what may well be the last chance to return to seagoing grandeur is that the inexorable trend is toward concealment of rettaliatory forces -- hence the commitment to a new generation of missile-carrying submarines and the shell-game MX missile system that the Air Force plans to build. Of the many virtues that can be claimed for a 46,000-ton battleship, concealment in the age of the orbiting spy satellite is not among them.

But that's no bother for the nostalgia wing of the U.S. Navy. As long as the old dreadnoughts remain afloat, the restoration movement will persist in trying to find an excuse for sending them back to sea.