The United States is reacting calmly to reports of a Soviet airlift of military supplies to Syria.
The Soviets appear to be moving with too little, too late. The superiority of American weapons used by the Israelis over Soviet arms used by the Syrians has dealt a blow to Soviet prestige in the Middle East.
Washington's main fear at the moment is that the fighting around the city of Beirut will escalate, causing an even greater loss of lives and property in Lebanon than has already occurred. American officials have been cautioning the Israelis not to move beyond the positions they now hold on the outskirts of the Lebanese capital.
Israeli Embassy officials, for their part, have been denying that Israel has any intention of going into the heart of Beirut. In order to underline its concern in this regard, the Reagan administration on June 15 described as tentative the President's scheduled meeting with Israeli Prime Minister Menachem Begin next week and ordered what amounts so far to a symbolic delay in the delivery of 75 F-16 fighter planes to Israel.
The administration had formally disapproved of the Israeli invasion, but then began to argue that it could serve as a catalyst for the creation of a new stability in Lebanon and a revival of talks aimed at resolving the Palestinian question.
Egypt's foreign minister, Kamal Hassan Ali, has been in Washington for the past few days, urging the Americans to prepare a new push to resolve the Palestinian problem. The Egyptians fear that if the Israelis stay in Lebanon and no progress is made on the Palestinian issue, it will have a ''radicalizing'' effect on many Arabs and provide the Soviet Union with new openings in the Middle East. At the same time, given the Israeli invasion of Lebanon, they see no alternative to suspending the Egyptian-Israeli negotiations over Palestinian autonomy.