After the latest developments in the USS Iowa gun-turret explosion case, the Navy's chief investigator, Adm. Richard Milligan, could be seen on an old tape telling Mike Wallace of CBS that it couldn't have been an accident.

But recent tests insisted on by Congress and the General Accounting Office show that the blast could indeed have been an accident, after all. ''Over-ramming'' the powder bags in the gun's open breech could have caused it.

Sen. John Warner (R-Va.) urges us not to ''jump to conclusions'' on the basis of the new evidence in consideration of the families of those who died. But that was just what the Navy did on the basis of the old evidence -- or lack of it. It blamed the explosion on a dead gunner's mate who could not defend himself, Clayton Hartwig; and it explained the action as the plot of a suicidal depressive. And it did so, obviously, with little delicacy of feeling for Hartwig's family.

In any event, Sen. Sam Nunn (D-Ga.), whose word is authoritative, views the Navy's case against Hartwig as having been ''eviscerated.'' The only remaining question is why the Navy, having every good reason to be cautious, clung so doggedly to a half-cocked theory.

For many, a new conspiracy theory has replaced the old one: it was, they say, a transparent exercise in Navy self-interest. For if the Navy's report had so much as hinted at the possibility that nearly 50 sailors perished in the Iowa blast because the technology of its World War II-vintage guns is defective, that would be doom for battleships -- possibly for all time.

And indeed you have to be lacking in historical imagination to be without feeling for the Navy's view of its battleships. These magnificent craft were once the defining weapons of the Navy and even of national power itself. It was an affront to the old Navy when the power of aircraft carriers and submarines had to be admitted, and battleships were relegated to a supporting role.

During the ambitious reign of John F. Lehman Jr. as Navy secretary under Ronald Reagan, a few old battlewagons were brought -- at some expense -- out of mothballs. There was some bold talk about their revived strategic value in the ''projection of power.'' It was a welcome reprieve from the knackers.

So for some, Navy self-interest suffices to explain the Navy's mulish denial that the Iowa explosion might have been accidental, and its clinging to the Hartwig depression/suicide theory.

If, as is possible, the Iowa disaster was viewed as a crisis for the Navy, the Navy probably reacted as institutions often do in the face of the unexplained. It indulged in stonewalling and scapegoating. This reaction is far from unique to military organizations. But since they depend on an especially intense code of personal loyalty, they're more vulnerable to self-protective obtuseness than most institutions.

The Iowa matter, with its disgraceful pinning of unsupported charges on a single man, constitutes a minor Dreyfus case. The parallel is inexact but instructive. Nearly a century ago, the French army cashiered Capt. Alfred Dreyfus and shipped him off to Devil's Island on what finally turned out to be trumped-up charges of spying for the Germans.

That Dreyfus was Jewish added complications, for the agitation in his behalf stirred up the latent antisemitism of the French military establishment of the time. Dreyfus was ultimately vindicated, but the French army never gracefully admitted its error.

The enduring point of the Dreyfus case, a pivotal episode in modern history, is that institutional inertia and pride are mighty forces, against which the abstract claims of individual justice are difficult to vindicate. Even in the face of decisive evidence that Dreyfus had been falsely accused, defenders of the French army stubbornly argued that it would be dangerous and damaging to service and national morale to admit it.

This is an old, but always consequential, argument -- the claims of individual justice clashing with an institutional, national or tribal interest. And for a free society, the desirable outcome should never be in doubt: it is justice to the individual, whether his name is Captain Dreyfus or Petty Officer Hartwig, regardless of institutional inconvenience or embarrassment.

I wonder, by the way, what midshipmen learn these days about the Dreyfus case at Annapolis. They do teach history there, don't they?