President Saddam Hussein's newest and perhaps harshest threat to attack Tel Aviv the instant war is waged against him will not alter Prime Minister Yitzhak Shamir's secret pledge to President Bush not to retaliate without "full consultation" with Washington.

Israel's faithfulness to this pledge would give the United States, not Israel, ultimate control over how and when to counterattack. The payoff to Israel for this surprisingly large concession was considerable: U.S. consent long sought by Israel to give the Jewish state top-rated and updated intelligence available to no other country.

Because of its extreme sensitivity, the Bush-Shamir pact, reached in the Oval Office Dec. 11, will not be acknowledged by either side. It is viewed by the president's senior advisers as an imperative for keeping the shaky, anti-Saddam coalition together if war starts. It commits the United States to retaliation against Saddam, preferably with no Israeli help at all.

Officially the White House ridicules the danger of defection by Arab coalition members if Israel -- possessor of nuclear bombs and a frighteningly large arsenal of other, mostly American-made weapons -- is attacked by Iraq and retaliates. But privately, fear runs high that political outrage fueled by Islamic fundamentalists could force policy changes inside Syria, Egypt and even some of the Gulf emirates if they suddenly found themselves in an alliance with Israel against Iraq.

Accordingly, the secret Bush-Shamir pact is designed to delay or avoid altogether Israel becoming in its own right a member of the anti-Saddam coalition. That required Israel's willingness virtually to peel off a piece of its sovereignty, but in its own interest and that of its irreplaceable benefactor. Shamir's assent may also be veiled evidence he is now convinced that Bush really does intend to go to war, as Israel wants, to wipe out Saddam's vaunted military power.

The policy change by Arab coalition members that might follow Israel's joining the coalition is purely conjectural. Some military commanders, however, have had nightmares of sudden Arab softness in the American rear, including sabotage and terrorist acts, if Moslems came to a full understanding that they were engaged in helping to defeat the Arab state that is Israel's most feared enemy.

The deal Shamir cut with Bush may not be all that popular back in Israel. Arab-hating war hawks like Housing Minister Ariel Sharon have long counseled tougher Israeli action against the Arabs. Indeed, their primal political purpose the last two decades has been to maneuver the United States into diverse anti-Arab postures, from blocking Arab arms sales to using America's economic clout to break the anti-Israel Arab embargo.

Once the United States actually got itself committed to war against Saddam, and could not turn back, these Israeli hawks would not cry many tears if Israel's entry into the war turned America's Arab allies into anti-American enemies. That would reduce Arab influence in Washington over eventual settlement of the Arab-Israeli struggle.

But Shamir has a powerful ally in his cabinet: Defense Minister Moshe Arens. Arens is a former ambassador here who knows George Bush well and is wholly aware of the importance Bush places on keeping Israel out of his crusade against Saddam Hussein. He stands solidly with Shamir in accepting Bush's appeal for full consultations with the United States if Saddam should send his ballistic missiles against Tel Aviv armed with chemical warfare agents.

The precise intelligence information Bush promised to start flowing to Israel is not known. The intelligence community here swears it could not be the "real time" intelligence that has long been Israel's highest aspiration but a gift the United States will not give. Speculation centers on giving Israel the earliest possible word about U.S. and Iraqi "operations" and possible insights into new uses of advanced technology by Arab armies.

When Iraq fired Scud missiles several weeks ago, they went from east to west, a direction leading to only one possible target: Israel. Although they were only tests, could Israel be certain? The new agreement may guarantee Israel an immediate U.S. intelligence readout of such future tests.

Or, as an Israeli official told us, "We want to know what is the first aircraft to raid Baghdad as war starts. Is that an American plane, or an Iraqi decoy?"

Israel will find out, at a price Bush hopes will be paid if Saddam ever drops his missiles on Tel Aviv: Let Uncle Sam handle it.