American relations with Syria, which improved after President Reagan advanced proposals for a Middle East settlement on Sept. 1, 1982, have since deteriorated. These proposals had at first kindled a faint though skeptical Syrian hope that the United States might indeed be about to launch an important new Middle East initiative in which resolution of the Palestine issue and withdrawal of the Israelis from occupied territory would be an integral part.
One of Syria's concerns had been that when the US government talked publicly about Israeli withdrawal from occupied territory, it rarely mentioned the Golan Heights. Clarification by the State Department spokesman that President Reagan's proposals were intended to encompass these heights helped alleviate this concern - especially in the wake of the strong public US condemnation of the Israeli annexation of the Golan several months earlier.
Syrian Foreign Minister Khaddam's relative forthcomingness during his three trips to the US in late 1982 suggested that the Syrians were at least prepared to give the US the benefit of the doubt. Syria welcomed Secretary Shultz's reassurances to Khaddam that the US envisaged Israeli withdrawal from the Golan Heights in the context of a peace settlement. Another positive American gesture was the secretary's acceptance in principle of Khaddam's invitation for him to visit Syria. Meanwhile, Khaddam assured the secretary that Syrian military forces would withdraw from Lebanon if the Israelis did likewise.
In the last several months, however, US-Syrian relations have cooled. Among the reasons for this are the US failure to get Israel out of Lebanon, the absence of forward movement on the September proposals, the intensification of Syrian news media attacks against the US, and the introduction into Syria of Soviet long-range surface-to-air missiles manned by the Soviets. It is the latter, in particular, which has stirred up the US government.
Both Secretaries Shultz and Weinberger have expressed serious concern over the introduction of the SA-5s into Syria. Shultz characterized this development as ''sobering and destabilizing,'' while Weinberger expressed the view that it made Syria an ''outpost of the Soviets.'' Although the original decision to introduce these missiles was apparently made by Brezhnev, its reaffirmation by Andropov sent a clear message to US authorities. The fact that the missile sites are being manned by Soviets raises disturbing implications regarding a possible Soviet involvement in any future Syrian-Israeli confrontation.
US concern in this regard flows from the current Israeli propensity to embark unilaterally on reckless military operations without regard for broad US interests. The new Israeli minister of defense, Moshe Arens, has been quoted as saying that the Israelis may have to take the missiles out in a preemptive attack.
There is also worry that the Soviet SAMs might be used against Israeli aircraft flying outside Syria. For seven years now - ever since Syrian forces entered Lebanon in 1976 - Syria has been humiliated by Israeli supremacy in the skies over Lebanon. Either Syria has chosen to ignore the Israeli aircraft or from time to time to challenge them in order to demonstrate that Syria is a bona fide Arab ''confrontation state.''
Almost invariably on these latter occasions Syrian aircraft have been shot down ignominiously - by the most advanced American fighter planes provided to Israel for ostensibly defensive purposes only. Israeli use of AWAC-type aircraft flying off the Lebanese coast has enabled the Israelis to zero in on Syrian aircraft as they take off from Syrian airfields. Now the Syrians have a counterweapon. Will they use it?
It is probable that except under the most exceptional circumstances the Syrians and Soviets will limit the use of the SA-5s to the defense of Syria and of Syrian forces in Lebanon. Thus, unless Israeli aircraft fly over Syria or attack Syrian territory or attack Syrian forces in Lebanon, the SA-5s are likely to be more of a potential than an immediate threat. The missiles are unlikely to be directed at Israeli aircraft flying over Lebanon merely on reconnaissance missions. However, in the event of an Israeli preemptive strike on Syria or on Syrian forces in Lebanon the SA-5s can be expected to be directed at Israeli aircraft anywhere within a 150-mile radius.
One must keep in mind that Syrian President Assad still does not want a full-scale war with Israel because this might mean the end of his regime. He will therefore continue to act in such a way as to avoid such a war. But having been so humiliated militarily by Israel, including losing over 80 planes in the skies over Lebanon last summer, and now being able to count on more effective Soviet support, he seems to be prepared to take more of a risk. In any case, the final decision regarding use of these missiles will be made by the Soviets, who presumably also want to avoid a war - especially with the US.
A potential confrontation underscores more than ever the importance of maintaining a US-Syrian dialogue - not to speak of a close US-Soviet and US-Israeli dialogue - in order to clarify intentions and to avoid misunderstandings. In this connection, the US must recognize and capitalize on the fact that the Syrian rhetoric obscures a reality - which many people find difficult to accept - namely, President Assad's underlying readiness to make peace with Israel on the basis of UN Security Council Resolution 242, under the right circumstances. Indeed, President Assad's interest in peace with Israel is an important reason why Syria has kept the door open to the US.
Assad knows that only the US can ultimately and potentially deliver Israel with regard to a just and comprehensive Middle East settlement. In addition, Syria recognizes that only US influence can conceivably get Israel out of Lebanon. In the past also Syria, as a self-styled ''nonaligned'' power, has considered that a relationship with the US offers an alternative to too tight a Soviet embrace. With the recent introduction into Syria of Soviet-controlled missiles, however, Assad has become more dependent on the Soviets - certainly insofar as use of the SA-5s is concerned.
Ironically, a move by King Hussein to enter peace negotiations with Israel, which the US government hopes would make it possible to induce Israel into making the necessary concessions, would not be well received by the Assad regime. Because of Syrian-Jordanian hostility rooted in a number of factors, Syria has feared that Hussein, like Sadat, might go it alone with Israel; and once again Syria would be left out of the peace negotiating process, further isolated and with diminishing prospects of achieving its own prime objective: recovery of the Golan Heights.
Accordingly, should King Hussein take the peace plunge it would be important for the US in its dialogue with Syria to stress that Hussein's action is viewed by the US only as the penultimate step in a process toward a comprehensive settlement which is ultimately to involve Syria and an Israeli withdrawal from the Golan Heights. If the US is unconvincing in this regard, Syria can be expected to do its best to sabotage Hussein's efforts - which would erode further the US-Syrian relationship.