If you think Doomsday ought to be delivered in 30 minutes rather than six minutes, then the proposed Soviet-American missiletreaty is a major advance for civilization. The 24-minute bonus is this: The Soviets' 1,320 warheads and the United States' 316 that would be unscrewed are on medium and short-range missiles that need only six minutes silo-to-target flying time. The treaty doesn't cover long-range strategic missiles 30 minutes away from the kill zones.

With 24 extra minutes -- time enough for a last meal, or at least the first course or two -- humanity can thank Ronald Reagan and Mikhail Gorbachev for bringing annihilation to us less hurriedly.

By number, the nuclear arsenals of both countries would be reduced by less than 5 percent. Fifteen years have passed since the last arms agreement and eight years since negotiations commenced for the current one. If eight years are needed to strip the globe's suicide gears by 5 percent that means, if the pace holds, 152 years will pass if the earth is to return to its pre-1945 non-nuke state. By 2139, statesmen can then devote themselves to stopping non-nuclear wars and conflicts that in 1987 were killing more than 40,000 people a month.

Among those who think about bombs and favor agreements to keep them unlaunched, the Intermediate Nuclear Force (INF) treaty has created two intellectual camps: the let's-be-grateful-for-small-steps people and those wanting the United States to make large leaps ahead with other weapons to compensate for what will be given up.

Small Steppers say loudly that they are not fans of Ronald Reagan and remember well his opposition to the 1963 Limited Ban Treaty, the 1972 ABM Treaty, the Outer Space Treaty and every other strategic treaty involving the Soviet Union. Nor do they ignore the suspicion that Reagan, not wanting to go down in history as the political incompetent who gave the nation its largest deficit ever, seeks to finish up as a peacemaker. But a small step is still a step. Nuclear treaties are rare on the horizon. Let Reagan be known in history as the Halley's Comet of peacemaking.

Small Steppers worry that when the ratifying Senate is through with the treaty the step may become a stumble. The Jesse Helms-Jack Kemp faction of the hard right is ready with restrictive amendments. Kemp, titular head of a standing army of reactionaries ready to shoot at anything that moves in the forest of Soviet relations, says the INF treaty is "a nuclear Munich that could imperil NATO's future." Flanked by such No Steppers, the Small Steppers have little risk of losing their current credentials on the left.

The greater risk is future credibility. If it turns out that the INF arsenal given up by the United States is replaced by other weapons, then the small step will have meant nothing more than one step forward and two backward. The current issue of Nuclear Times says the "partial arms-control agreements are like attempts to strain spaghetti with a tennis racket: A lot of noodles slip through." It reports that the push in NATO is for more post-INF weapons: "a new short-range battlefield nuclear missile, a free-fall nuclear bomb and additional F111 fighter-bomber squadrons to deliver them, an air-launched missile, sea-launched cruise missiles and improved conventional forces."

With the nation's eyes on the INF prize, possible alternative war scenarios are on the minds of Large Leapers. One of them is Rep. Les Aspin (D-Wis.), chair of the House Armed Services Committee. In a speech last Tuesday, he said that with the INF treaty "a done deal," the time has come to ponder such disparities as the Soviets' tank advantage: 50,000 to NATO's 20,000. To enhance European security, Aspin says, "We can build antitank barriers -- dirt trenches, canals, concrete walls, mine fields." He sounds like a reserve colonel on summer maneuvers with the Corps of Engineers.

While the congressman's style of leaping wants to replace the Maginot Line with the Aspin Line, the "Star Wars" lobby -- which leaps into space -- is saying that no less than a trillion dollars is needed for its venture. Those who want the land and skies free of pending holocausts see nothing changed by INF. A treaty worthy of strong, not reluctant, support would require that the elimination of the intermediate missiles not be undermined by the addition of other weapons.

Treaties that don't face the delusion of war -- that military violence is rational -- are treaties that don't treat