The United States sought quickly to restrain Israel from responding to Iraq's missile attack on Israeli territory last night out of fear that an Israeli decision to join the war could tear apart the anti-Iraq alliance of Arab and Western nations.

The Israeli ambassador to the United States, Zalman Shoval, told reporters that his nation "reserves the right to respond in any way we deemed fit" to what he called "an unprovoked attack."

Secretary of State James A. Baker III telephoned Shoval from the White House after an emergency meeting there, and Baker later phoned Israeli Prime Minister Yitzhak Shamir. According to a White House statement, Baker "assured the prime minister that the United States is continuing its efforts to eliminate this threat."

Baker and Deputy Secretary of State Lawrence S. Eagleburger, who returned from Israel last weekend, conveyed the "heartfelt sympathy" of the United States to the Israeli government and said they were "devastated" by the attack, the ambassador said.

Baker promised Israeli Foreign Minister David Levy last year that the United States would provide an "appropriate response" to any missile attack on Israel, a commitment he restated last week during a tour of Arab capitals. U.S. officials said an escalation of the U.S. air war against Iraq likely would result from the missile battering aimed at Israel.

Baker also telephoned the ambassadors of Saudi Arabia, Egypt and Syria, the three main Arab partners in the international coalition opposing Iraq, according to State Department spokesman Margaret Tutwiler.

In planning for the gulf war, U.S. officials had worried that Iraq would strike at Israel, as Foreign Minister Tariq Aziz threatened in Geneva a week ago. They feared such a provocation could draw Israel into the conflict, creating doubts whether the Arab allies in the coalition would be willing to fight on the same side as Israel.

Syria, in particular, said it would oppose any Israeli involvement in the war. Syrian President Hafez Assad has already made clear he would not join any offensive campaign against Iraq, and his foreign minister, Farouk Charra, said Syria could not accept any Israeli involvement in the conflict, even if it were in retaliation for an attack on Israel.

Egypt's President Hosni Mubarak had said he would not oppose retaliation by Israel if it was attacked first, but said Egypt did not want any preemptive attack by Israel. Baker said that Saudi King Fahd had expressed similar views.

Last night, Shoval said that Israel reserved the right to defend itself, "without going at the present time into particulars what the decisions of the Israeli government with respect to that will be."

Shoval noted that Israel had heeded American demands that it keep a low profile in the gulf crisis. Shoval said six or seven injuries had resulted from the missile attack, but there were no reported fatalities so far. He said there had been extensive property damage.

On his visit to Israel, Eagleburger had sought to work out a coordinated plan for a military response, should Saddam Hussein follow through on his threat to attack Israel. At least publicly, the Eagleburger mission seemed to underscore the differences between Israel and the United States, with Israeli officials saying they were reluctant to put the defense of their nation in U.S. hands.

An official of an American Jewish organization with close ties to Israel said yesterday he believed that the Israeli government would feel compelled to retaliate for any attack.

This official said that the Israelis had flatly refused to give Eagleburger a guarantee they wouldn't retaliate against an Iraqi attack. But the official said that Eagleburger returned to Washington reassured somewhat because Israel did promise that it would weigh the nature and scope of an Iraqi attack and calibrate its response.

The official said that while it apparently wasn't spelled out, Eagleburger believed that if the Iraqi attack was limited to conventional warheads and small in size, Israel might even refrain from responding.

For the U.S. part, the official said, Eagleburger moved toward meeting Israel's desire for a command-and-control mechanism that would allow U.S. and Israeli forces to coordinate their actions if both became involved in fighting.