A few days ago, behind closed doors in a "situation room" at the Georgetown Center for Strategic and International Studies, an expert group of former national security officials with bipartisan backgrounds played out a hair-raising "war game." It was all about a hijacking, with a nuclear twist and an ending with significant lessons for those engaged in the real-world struggle against state-supported international terrorism.

If I tell you the lessons now, it will give away the ending, so bear with me. First the cast: As president of the United States, there was James Woolsey, former undersecretary of the Navy in the Carter administration. The Democratic chairman of the House Foreign Affairs Committee, Les Aspin, played White House chief of staff. Eugene Rostow, once undersecretary of state for political affairs in the Johnson administration and later head of the Arms Control and Disarmament Agency for Ronald Reagan, was secretary of state. Reagan's former national security adviser, Robert McFarlane, was secretary of defense. Retired Gen. Brent Scowcroft played the role he played in the Ford administration, national security adviser. (Veteran television newscaster Daniel Schorr was White House press secretary.)

The high crisis they confronted is the hijacking by four terrorists (two West Germans and two Arabs) of an American-owned "Air-Med" airliner en route from Munich to Rome. With a sense of recent history, the game's designers fetch the plane up at the same NATO air base at Sigonella in Sicily, where U.S. Navy F14s forced down the Egyptian 737 carrying the hijackers of the Achille Lauro.

sk,3 There is a bomb on board and, unbeknownst to the terrorists, it is radioactive, leaking cobalt 60, slowly poisoning the passengers. The "crisis managers" are aghast and at a loss as to how to storm the plane without having the bomb blow up. Before they can act, it does -- destroying the air base.

Enraged and vengeful, the decision-makers are unanimously in favor of retaliation. Libyan harbors are mined and port facilities bombed. Then, suddenly, the investigation turns up evidence. The finger of guilt swings to Syria. The case is "irrefutable," as the Reagan administration is given to putting it, and enough of it becomes public knowledge so that it is impossible to ignore. But the Soviets, seeing the punishment that has been administered to Libya and assuming that something of the same sort threatens Syria, become "very aggressive" about what they will do if Syria comes under attack. According to one participant, the script the war-gamers had to work with convincingly conveyed a real threat of a U.S.-Soviet confrontation of unpredictable dimensions.

sk "All of the participants were forced into the same trap," says Robert Kupperman, a resident terrorist expert at CSIS, who stage-managed the war game. "There was a lot of tough rhetoric when it was just Libya," he reports. But when it became Syria and the Soviets, "they began to see the limits on action." And so, after due deliberation of the options, the war-gamers decided to break diplomatic relations with Syria and apply stiff economic sanctions.

sk,3 Now you can argue how well or badly the game was played; besides, it was only a game. There is a lesson in it, nonetheless: Insofar as retaliation is one of the weapons in countering or deterring terrorism, circumstances alter cases; it is not always a matter of simply finding a "smoking gun" and then, Pow! The administration learned just that in 1983 when terrorists blew up the Marine barracks in Lebanon, and Caspar Weinberger said, "We have a pretty good idea of the general group from which they came, and, as I said the first day, they are basically Iranians with sponsorship and knowledge and authority of the Syrian government, and that has not changed." But the administration did not bomb Syria or Iran.

sk,3 And so, to its credit, the administration is learning in the aftermath of the attack on Libya. Shortly thereafter, President Reagan said he would use force against state-sponsored terrorism from Syria or Iran if he had the same kind of evidence he had of Libya's complicity in the bombing of the West Berlin disco. But shortly thereafter, Secretary of State Shultz said the president "had some words put in his mouth by a question, and did not mean to say that we had a plan for attacking Syria or Iran." Rather, he said that it was important for the world to know that we had "that tool . . . in the bag," along with a lot of other "available means."

sk Confronted with mounting intelligence findings -- by the British, the West Germans and the Israelis -- implicating Syria not only in the discotheque bombing but the terrorist attacks on the Rome and Vienna airports and the attempt to blow up an El Al airliner in London, the administration has been wisely circumspect in its endorsement of this evidence and the uses it has made of it.

When you are talking about "smoking guns," it is only prudent for the U.S. government to rely on its own smoke detectors -- and on its right to decide for itself whether the gun is smoking. When you are talking about the difference between a Libya, say, and a Syria, a foolish consistency is a prescription for something foolhardy.