FOR President Bush and his small handful of top advisers, the next major decisions concern how far to take the battle to free Kuwait to Iraq itself. In its first two days the ground war began much as the air war had - progressing so one-sidely that officials were warning the public against euphoria. But House Armed Services Committee chairman Les Aspin, who has correctly outlined each major step of this war before it occurred, said Sunday he expected Kuwait to be taken in three or four days. A fast, efficient victory could represent a triumph for President Bush's effort to shape America's leading place in world affairs after the cold war. Flexible and pragmatic on most issues, Mr. Bush has defined a moral order in the Persian Gulf in stark and very personal terms and brooked no compromise. He has given the exercise of power a highly cooperative character, but the power is essentially American. Tough battles remain a strong possibility in the Gulf war. Iraq is fully expected to fire chemically armed artillery shells. The Republican Guard troops may yet represent a concentration of Iraqi fighting power that had been drained from Baghdad's front-line troops. But even the most pessimistic scenarios fall far short of envisioning the long war many feared during the last seven months. If the war continues to progress quickly with light casualties, then it becomes easier to keep war aims modest and even to live with a Saddam Hussein stripped of prestige and much of his arsenal. ``We could live with Saddam'' still in power, says Marvin Feuerwerger, strategic fellow at the Washington Institute for Near East Studies, ``especially if much of his equipment was left behind.'' The coalition strategy includes sweeping as deep as 100 miles into southern Iraq to isolate all enemy forces in the Kuwait theater of operations. This may eliminate the risk that Iraq could withdraw its forces to just across its border from Kuwait, forcing the coalition to decide whether to chase them north. Much of the political response to this war has always hinged on how quickly and cleanly the fighting could be concluded. Even for Iraqi soldiers, a senior administration official has said, a fast and efficient war of the kind the US planned would cut down the loss of life. A decisive victory also helps ensure that the US can withdraw most US troops from the region when the war is over. Secretary of State James Baker III suggested over the weekend that any post-war peacekeeping forces would have an Arab face. President Bush showed no sign of overconfidence in launching the ground war. On Saturday, White House spokesman Marlin Fitzwater described him as ``somber, very serious,'' and concerned about the loss of life possible in ground combat. The president's public demeanor seemed to bear this description out. Bush appeared grave and abrupt Friday morning when he strode out of the Oval Office and into the Rose Garden to announce his ultimate deadline for Saddam Hussein. But Bush was not going through agonizing decisions, as he was before launching the war in January. Then, as he decided when to initiate war against Iraq, he showed a reflective side that is somewhat out of character: Aides said he was not as lighthearted and gregarious as usual. Decision came last week Early this week, Bush's chipper affability returned. He even pantomimed a mock press conference as he walked around the Rose Garden past reporters watching him through glass doors. He worked long and energetic hours to hold the coalition together while seizing the initiative back from the Iraq-Soviet negotiations, aides say, but he faced no soul-searching decisions. In fact, the decision on the day and hour to launch the ground war had been made more than a week earlier. American war plans were never altered through all the dealmaking between Baghdad and Moscow. Gen. Norman Schwarzkopf, commander of the Gulf forces, had chosen the hour of the ground assault within days after Feb. 11. He was authorized to carry out the attack unless the president postponed it. Soviet manuevers When the Soviets entered serious negotiations with Baghdad last week, the chief concern at the White House was not to allow either the Iraqis or the Soviets to manipulate diplomacy to forestall the ground war. ``We cannot be kept hostage to maneuvers like that,'' a senior administration official said on Thursday. Although some outsiders saw the Soviet gambit as a return to cold-war competition with the US for spheres of influence, the administration appears to have taken the Soviet efforts in good faith. ``I think the administration rightly felt that the Soviet move was a reasonable one, not an unfriendly act,'' says former diplomat Raymond Garthoff, now an East-West relations expert at the Brookings Institution. Thursday evening at the White House, Bush's top national security advisers were gathered to detail what Iraqi compliance with the UN resolutions would mean. Joint Chiefs of Staff Chairman Colin Powell suggested using the scheduled ground assault time as a deadline for the Iraqis. The deadline snapped the crisis back into American control, without visibly disturbing the US-Soviet relationship, whose importance is seen by many as dwarfing the stakes in the Gulf. -PATHNAME- /usr/local/etc/httpd/plweb/DBGROUPS/paper/database/tape/91/mar/week10/abush.