SIX weeks ago the conventional wisdom held that the United States bombing of Libya not only was inappropriate and ineffective but would actually trigger a violent backlash. Everything that has occurred since the April 15 air strike belies the conventional wisdom. In fact, the available evidence indicates that the President's antiterrorist strategy has produced positive results at three levels -- among the organizers of state-sponsored terrorism, among their patrons in the Kremlin, and among US allies.
Libya's Muammar Qaddafi, far from escalating his attacks, has retired into a state of international purdah. His threats to turn the Mediterranean red with American blood have been muted; there is tenuous evidence that he has canceled terrorist operations in Sudan and elsewhere.
Syria's Hafez Assad has also gone on the defensive. He has publicly denied allegations that his government has been implicated in international terrorism and has gone so far as to hint that he is working to secure the release of Western hostages held by Shiite gangs in Lebanon. And to polish his image, he recently made his first visit to the West in eight years, a trip to Athens to woo European opinion.
It would obviously be naive to interpret the current behavior of Colonel Qaddafi and Mr. Assad as evidence that they have renounced sponsorship of terrorism. But it would not be unreasonable to conclude that they have been compelled to recognize that the rules of the game have changed in a way that requires them to reconsider the odds. If they contemplate future attacks such as the Dec. 27 airport massacres or the April 5 bombing of a West Berlin discoth`eque, they must calculate the potential consequences if they are linked with the crimes.
``Qaddafi,'' a State Department official says, ``must be debating whether the murder of an obscure American official in Sudan is worth the possible damage that Libya will suffer as a consequence.''
There are signs, also, that Qaddafi's and Assad's supporters in Moscow are concerned about the new risks involved in state-sponsored terrorism and are counseling restraint. In late May, Soviet General Secretary Mikhail Gorbachev met in Moscow with Qaddafi's chief deputy, Maj. Abdel-Salam Jalloud, and with Syria's Vice-President Abdel Halim Khaddam. Mr. Gorbachev pledged continuing support to his two visitors, but at the same time he warned Qaddafi to refrain from terrorist acts that could be used as ``pretexts'' for ``imperialist attacks.''
This is consistent with long-established Kremlin behavior in the third world. The Soviets have a record of exploiting local tensions and conflicts, including the backing of terrorism, to undercut Western interests and advance their own influence. But they are exceedingly careful to avoid being drawn into hostilities by client states, above all in situations involving the risk of superpower confrontations. That now is a danger inherent in their ties to the two states most closely identified with terrorism.
As for US allies, after having previously paid only lip service to President Reagan's policy of punishing sponsors of terrorism, they have closed ranks to issue a statement at the Tokyo summit in early May singling out Libya as a state sponsoring terrorism and pledging punitive action, including arms embargoes, against such countries. They have taken their first step to translate the commitment into action by expelling Libyan diplomats implicated in murders in Europe. The change is most significant in Italy, which has substantial economic stakes in Libya.
Even with increasing allied support, Mr. Reagan's strategy still faces its most critical test -- what sanctions to apply against Syria's Assad if and when convincing evidence emerges of his complicity in terrorist attacks. Punishing Assad, with his key role in Middle East affairs and his treaty with Moscow, is different from retaliating against an isolated, eccentric Qaddafi. If the Western allies can't agree on sanctions, Assad must seriously weigh the possibility that Israel would take it upon itself to punish terrorists.
Where, then, do all these developments since the April 15 US raid on Libya leave President Reagan's war on state-sponsored terrorism? No one could claim that his strategy has neutralized the threat. But it surely must be a significant gain that the murder of innocent civilians in foreign lands is no longer a risk-free, cost-free enterprise for governments.
Joseph Fromm, a veteran foreign correspondent and former assistant editor of U.S. News & World Report magazine, is US chairman of the International Institute for Strategic Studies and a fellow at the Johns Hopkins School of Advanced International Studies.