The White House's restrained expressions of regret do scant justice to the 290 victims who died at U.S. hands in the Persian Gulf Sunday. Yet while horrifying, it was nonetheless an accident. On present evidence, it's hard to see what the Navy could have done to avoid it.

Modern naval warfare and the crowded skies of the gulf have combined to make the stage conducive to tragic accidents. The first occurred in May of last year when an Iraqi plane mistakenly attacked the American frigate Stark. It's too early to assess blame for the new tragedy, the shooting down of an Iranian Airbus by the U.S. cruiser Vincennes. But if the Navy's account of events turns out even approximately correct, Captain Will Rogers of the Vincennes had little choice.

The ship was not only in a combat zone; but at that very moment was engaged in action against Iranian gunboats making high-speed runs against it. Then Captain Rogers's radar operators reported an aircraft heading toward the ship and descending. The plane, which had taken off from Iranian territory, was reportedly flying five miles outside the civilian air corridor and failed to answer three warnings over the civilian distress channel that all aircraft are supposed to monitor.

The radar operators apparently had indications, which the Navy refuses to discuss, that the plane was a powerful F-14 jet. That inference was tragically in error. Iran now says the plane was within its corridor. Its speed, 450 knots, was more typical of civilian flight than an F-14 attack. And it is not yet clear why sophisticated radar did not distinguish between an F-14 and a much larger Airbus. Still, put yourself in Captain Rogers's shoes. These contrary pieces of evidence would have weighed lightly against other evidence suggesting an imminent attack. Iranian F-14's had recently been seen in the region; U.S. forces had been warned to expect attacks around July 4; and Captain Rogers already had a battle on his hands. Barring surprising findings, it is hard to fault his decision to attack the suspect plane.