At a White House briefing a few hours after the American attack on Iranian oil platforms in the Persian Gulf, presidential spokesman Marlin Fitzwater was asked: å"The Iranians are already suggesting that there will be retaliation. . . . Why should we think that this won't go on response for response?" Answered Fitzwater: "I would emphasize the restrained nature of this action, the precision with which we tried to identify a target which was proportional to their attack." And "we gave . . . advanced notice so that they could escape and thereby save lives."

So there we have it: restraint, precision, advance notice and, above all, proportionality. Combat so gentlemanly it cannot fail to impress the ayatollah. No reason for him to strike back. After all, we seek no wider war, as LBJ used to say.

The idea of proportionality, that restraint begets restraint, continues to mesmerize American policy makers. One would think they had learned something from Vietnam, the laboratory, the graveyard, of the idea of proportional warfare. Our policy of gradual escalation -- "graduated pressure" -- did not deter. It simply ensured ever rising levels of stalemate, the level being decided by the other side.

And if not in Vietnam, proportionality should have met its ruin in Beirut, where the United States adopted rules of engagement of absurd proportionality. A Marine who found himself under sniper attack was permitted to return fire (1) only after identifying exactly who was firing, (2) only if he used the same caliber weapon ("Let's see now. Is that guy trying to kill me with an AK-47? May I go up to an M-16, sergeant?"), and (3) only so long as the sniper kept it up. As soon as the sniper decided he had had enough, the Marine had to quit too. After being ordered to concede to the adversary control over the location, intensity and duration of combat, U.S. forces in Lebanon settled down to await their destruction.

On the other hand, the virtues of disproportion -- the application of force so sudden, overwhelming and irresistible as to demoralize and disarm the enemy and thus stop the violence -- have been amply demonstrated in such diverse places as Czechoslovakia (1968), Poland (1981) and Grenada.

The most recent demonstration was Libya. In retaliation for a Libyan terrorist attack that killed but one American, the United States last year launched a massive raid on Gadhafi which so devastated and demoralized him that neither he nor international terrorism has been quite the same since. Indeed, Libya has slid so far that this summer it was routed in its border war with hapless Chad. Not all this was due to the raid. But the raid contributed much by concentrating Libyan minds on the disproportion between what Libya could inflict and what it could be made to endure.

A demonstration of the real power imbalance between a loudmouth and a superpower is enough to put a country like Libya in its place. Conversely, once a superpower voluntarily accepts the constraints of proportionality, it forfeits that excess of power which makes it a superpower and which enables it to deter lesser powers.

Fitzwater got it exactly wrong. Proportionality is the enemy of deterrence. The way to ensure that tit-for-tat warfare will continue in the Gulf is precisely for the United States to restrict itself to responses that are, in the administration's proud and reiterated characterization of the oil platform attacks, "restrained, proportional and measured." (Indeed, Iran has already commented on the deterrent effect of the American action: yesterday it attacked the main Kuwaiti oil terminal with another Silkworm missile.) It is only under a regime of proportionality that Iran can carry on tit for tat against the U.S. Navy.

Iran does the one thing the United States warned it against -- firing directly at a U.S.-flagged vessel (blinding the American captain) -- and it is reproved with the most marginal attack carried out in the most genteel way: no Iranian soil, no Iranian soldier, no Iranian interest is disturbed. And just to be sure, the secretary of defense promises that there will be no more. Chapter closed.

The point of retaliation is not to make Iran bleed, but to make it stop. And you do that not with an exercise of destroyer target practice against abandoned oil platforms, but by striking a target of real strategic significance to the Iranian war effort, a target such as Kharg Island, from which Iran exports 90 percent of its oil.

Restrained, proportionate and measured. The message such a response sends is not that the United States will not tolerate any attack by Iran, but that the United States will not tolerate any engagement with Iran.

The point of administration restraint is a desire not to provoke. But that misses the point. The ayatollah has made it clear that what he finds provocative about the Great Satan is not its retaliation but its existence. The only way for the United States to stop provoking Iran is to leave the Gulf. And since Congress is not going to support any running gun battle in the Gulf, no matter how low the intensity, a couple more tit for tats and the ayatollah will have won again.