Israel's smoldering doubts about the Carter administration's policies in the Middle East have turned almost overnight into open alarm.

Before the Israelis had a chance to absorb the shock of Saturday's Soviet-American declaration on joint objectives for a Middle East peace settlement, they were jolted again by blunt public remarks of President Carter's chief foreign policy adviser, Zbigniew Brzezinski, about U.S. intentions to "exercise its leverage" to obtain a settlement.

Although the propaganda war has clearly begun, Israel's Foreign Office today preferred not to add any more fuel to the burning edifice of Israel-American unity until Foreign Minister Moshe Dayan has completed his scheduled meeting with President Carter in New York on Wednesday.

To some Western and diplomatic observers, Israel's reaction to the joint communiqe was surprisingly harsh, considering the ambiquity of the text. As one Israeli official said today, however, "ambiguity has its uses in diplomacy but not in this context."

The influential newspaper Haaretz said today that it is "important not to exaggerate the significance and possible resulting harm of the joint Soviet-American statement." The main danger, the paper said, was that the "statement may be taken by the public as replacing [U.N. Security Council] resolutions 242 and 338 as a basic for Geneva."

The most serious aspect of the statement, according to Haaretz, was "its reference to the legitimate rights of the Palestinian people - rights whose very vagueness gives them a limitless character . . . which Palestinians interpret as including the right to eliminate Israel."

Israel is "approaching one of its most difficult crises ever," the paper concluded.

An Israeli official echoed this today by saying that Israel would hang on to Resolution 242, which the communique did not mention, "with all our might" in order to block both the PLO and the concept of a Palestinian state.

Although Resolution 242 was also ambiguous, and its ambiguity was the reason it was accepted by all the parties concerned, the ambiguity of the joint Soviet-American communique is condemned here because it represents, in Israel's view, a shift in American policy toward the traditional Arab and Soviet positions.

Former Prime Minister Yitzhak Rabin yesterday blamed the deterioration of Israel-American relations on the "Miserable policy of the Likud government" which, he said, had managed in only three months to shake the political understanding that his party had built up over 10 years.

While such comments are to be expected from opposition leaders in a parliamentary democracy, political observers here believe that the Begin government's statements on retaining all of the West Bank and on Jewish settlements there have clearly damaged relations with the United States and further strengthened the Arabs' view of Israeli intransigence.

In fact, Dayan has been begging the government to play down these statements while such delicate negotiations are going on.

As Rabin is in a position to know from his meeting with Carter last March, however, Israel has been on a collision course with the United States since Carter took office. Both Rabin and Begin have tried to sweep U.S.-Israeli differences under the rug for domestic political purposes.

The basis for these differences, as many informed Israelis have long appreciated, is a well-known Brookings Institution report in which Brzezinski's views were reflected.

The report called for a comprehensive Middle East settlement and held out as an option the "provision for Palestinian self-determination, subject to Palestinian acceptance of the sovereignty and integrity of Israel within agreed boundaries." The report said that this might take the form of an independent Palestinian state or of a "Palestinian entity voluntarily federated with Jordan but exercising extensive political autonomy."

The report also said that Israelis and Arabs probably could never come to an agreement on their own and therefore "initiative, impetus and inducement may well have to come from outside." It added that in "all of this the United States should work with the Soviet Union to the degree that Soviet willingness to play a constructive role will permit."

There are informed Israelis who view everything that Carter has subsequently said and done, including the Soviet-American communique, as basically flowing from the Brookings report.

Israel may have been disappointed at the drift of American policy but analysts feel there was little reason for surprise except to the extent that Israel's leaders tried to gloss over these basic differences.

Rabin's government hoped to avoid a Geneva conference altogether, in the opinion of some observers here, because once a conference began it might be difficult to walk away from outside pressure to compromise.

Begin's government, on the other hand, embraced the idea of a Geneva conference but wanted to have it an open conference between Israelis and Arabs without the "initiative, impetus and inducement" that the United States clearly intended to impose.

If such a conference ended in deadlock and failure, as it almost certainly would, then Begin could say he tried and the onus for failure would not be put upon Israel's shoulders alone.

There is informed opinion in Israel that holds that neither the previous Labor government nor the current Likud goovernment ever really believed that a comprehensive peace is alike was ever remotely in the cards and that, in the end, the best that could be expected would be more interim agreements. If this view is true, then the difference between the approach of the Labor government and that of the Likud government is basically one of tactics rather than strategy.

What Israel fears now is that the United States is so commited to having a Geneva conference this year that real pressure may fall upon Israel now that it is out in the open that Israel-American differences are substantive rather than procedural.