U.S. presidential envoy Philip C. Habib arrived here today on his mission to find a solution to the Middle East missile crisis and was met with an official Syrian radio commentary accusing the United States of supporting Israel's policy of "Zionist aggression."

Coming from talks in Lebanon with government and political leaders -- and with the sound of renewed Beirut shelling still fresh in his mind -- Habib conferred with Syrian Foreign Minister Abdul Halim Khaddam and other officials. He was expected to see President Hafez Assad Sunday before traveling to Israel.

A diplomat suggested that the tough radio commentary was aimed at driving home to Habib the Arab world and domestic opinion that "those who want to dialogue with Syria must leave the sick at home."

Although threats do not frighten Syria" -- suggesting U.S. collusion with the Jewish state -- diplomats said the government was taking a softer line in private.

First Deputy Foreign Minister Nasser Kaddour, for example, called in some Western European ambassadors and for the first time reportedly hinted that Syria was worried that any conflict might not be limited to Lebanon, where SA6 ground-to-air missiles are positioned.

Despite Syria's public show of confidence bordering on truculence, the diplomats said, it had little choice but to pin hopes of avoiding a larger conflict on the United States.

Only the United States could exercise sufficient restraint on Israel to prevent Prime Minister Menachem Begin from trying to use the crisis as a justification for a full-scale war aimed at undermining the Syrian government, diplomats said.

Some diplomats expressed fears that removing the Soviet-built missiles by force would be so costly in lives that Begin might decide that an all-out war was only marginally less risky for him during the current election campaign.

The radio commentary accused Washington of "favoring Israeli policy of Zionist aggression and expansion and intentionally ignoring the role played by Israeli leaders and their threats."

Arguing that the missiles are in Lebanon legally as part of Syria's Arab League mandate to maintain order there, Syrian officials have said they wanted to avoid any conflict and that any war would be imposed by Israeli choice.

[In Jerusalem, Washington Post correspondent William Claiborne reported, Israeli Foreign Minister Yitzhak Shamir said that according to accounts he has received, Habib "has no chance" of persuading the Syrians to remove the missiles voluntarily. Shamir, in an interview on Israeli radio, said the diplomatic efforts to resolve the missile crisis should "be kept as short as possible."]

Various hints suggested that Syria was willing to withdraw the missiles if Israel stopped its air raids against Palestinian targets in southern and coastal Lebanon and ended its de facto alliance with the mainstream Christian militias in central Lebanon.

Begin and his ministers have basically rejected such demands during the past 10 days. But the French-language Beirut newspaper l'Orient-Le Jour today said Habib would propose to Syria a limited variation on this idea.

Under such a plan, the newspaper said, Israel would halt its air attacks in the Bekaa Valley where the missiles are located. In return, the Syrians would end their 6-week-old siege of the eastern Christian city of Zahle and withdraw from surrounding hills and mountain peaks.

Eventually, the Lebanese Army would take up those positions.

Although the United States is known to favor solving the missile crisis by working out face-saving arrangements on the ground in Lebanon, diplomats here were skeptical about such an approach.

Any movement on the ground limited to the Bekaa Valley, the mountains and Beirut itself could leave Syria's Palestinian guerrilla allies at the mercy of Israeli air and artillery attacks, according to this viewpoint, and Syria thus would continue to lose face.