While acknowledging no policy change, President Bush is undermining private predictions by Saudi war hawks and the Pentagon's "surgical strike" brigade that the United States will start war against Iraq on or about Oct. 18, the dark night of the Persian Gulf's next new moon.

Bush has seemed surreptitious in moving away from what has long been eyed by Saudi insiders, and a few eager Pentagon generals, as the first likely date to start bombing Saddam Hussein out of Kuwait and maybe out of Iraq. That would be followed by reinstatement of the Kuwaiti emir as the legitimate ruler.

But however veiled, Bush's move is real. His U.N. speech this week muffled war drums. It suggested a diplomatic solution to border problems after Saddam Hussein quits Kuwait. It even hinted at wrapping in the Arab-Israeli dispute and trying for a wider Mideast settlement.

Bush's speech got a sympathetic hearing in unlikely quarters. Two days later, the lead editorial in the New York Post, one of Israel's truest supporters, said war, Israel's favored solution, might be avoided by emulating President Kennedy in the 1962 Cuban missile crisis. That would mean getting Iraq out of Kuwait, imposing rigorous control over Iraqi armaments and permitting Saddam, like Fidel Castro, to retain power.

Presidential aides deny any change in policy, but insiders trace a subtle shift to several sources. The Soviet Union has alarmed the United States with a warning that it wants a non-war solution and will go to the mat in the United Nations against Bush if he starts war without clear provocation and without U.N. approval.

Moscow's smart initial support of Bush in the Gulf crisis gives it leverage. It gets more from France and other European powers that have backed the United States against Saddam with money (but few troops). They support the Moscow warning. If Bush moved alone, he might face a blast from the United Nations.

Bush is also said to be painfully aware that hopeful, early predictions of Saddam's vulnerability to political enemies in Baghdad have not yet been borne out. In addition, cautious Pentagon brass led by Gen. Colin Powell, chairman of the Joint Chiefs, never did agree with the ousted Air Force chief, Gen. Michael Dugan, that surgical bombing would produce quick, bloodless victory.

To the contrary, Bush is known to have been warned to expect a possibly high body-bag count. That is increasing pressures from his political advisers to go easy in stepping into a war that could undermine his presidency.

The slippery terrain of what had been considered Bush's virtual "war policy" has embarrassingly revealed itself to the White House on several occasions during the buildup to the 250,000 American troops soon to be in or near the Persian Gulf. An impeccable administration source told us that the Navy made a serious mistake in loading the Fourth Marine Expeditionary Brigade in East Coast ports last month. Short of Navy supply ships, called sealift, because of its insistence on building aircraft carrier task forces the past decade, the Navy overloaded its boats carrying the Marines and their equipment.

The Marines could not possibly have mounted a landing operation against Iraq from the Persian Gulf because of their extraneous baggage. That, not the advertised "training exercise," was the real reason the 13,000-strong brigade landed on the beaches of Oman this week: the brigade and its weapons had to be unloaded and properly "combat-loaded" before taking up its designated station in the Persian Gulf.

No one had envisioned this mistake, which delayed the brigade getting on station by almost one month, but there have been others. When Gen. H. Norman Schwarzkopf ordered the Navy to program cruise missiles on the battleship Wisconsin to take out key Iraqi targets, the Navy said it would take about a month: CIA and Defense Intelligence Agency spy cameras had failed to take the photographs needed to compose electronic terrain "maps" to guide the missiles to their targets.

Such mishaps baffled and angered senior planners. They also alerted Bush's men to the fact that in the actual prosecution of war, similar mistakes would probably be unavoidable and possibly a lot worse. That multiplies presidential doubts about the quick, bloodless victory predicted by some of America's Arab allies and Pentagon advocates of the efficacy of air power.

Bush's caution is matched by a stream of warnings from top-level military players no longer in office. One warning, known to be under close study by some of Gen. Powell's key aides, was written by retired Lt. Gen. William Odom, who played a major role in setting up former President Carter's Rapid Deployment Force for the Gulf. Odom compares the forecasts of quick, bloodless victory over Saddam to the spirit of Union forces just before their rout by the Confederates at Bull Run.

"It was going to be a turkey shoot," Odom wrote. In his new mood, George Bush is going to be mighty careful about buying any 1990-style "turkey shoot."