WASHINGTON - With President Bush and his top aides saying that the time for diplomacy is slipping away, military officers and defense analysts predict that the United States could once again be at war with Iraq as early as the third week in February.

Officers, active-duty and retired, and analysts predict that war would likely come between the mid-February end of the hajj, the annual Muslim pilgrimage to the holy Saudi Arabian city of Mecca, and early March.

Still, in a bid to gain the broad international support that he lacks, Bush has opened what officials call a "diplomatic window" of a few weeks to build international support and to give other countries a final chance to pressure Saddam Hussein to give up his chemical and biological weapons, or go into exile.

That window will probably remain open at least until Feb. 14 when United Nations weapons inspectors present their next report on Iraqi compliance with disarmament demands to the Security Council.

Longer delays, stretching into the spring, analysts say, could erode voter confidence in both Bush's leadership and the U.S. economy. Such delays could also have an adverse effect on the support of Mideast allies for a U.S.-led invasion and the fighting edge of frontline American troops stationed in Kuwait and neighboring countries and aboard ship.

Tens of thousands of U.S. troops are pouring into the Persian Gulf region, while huge cargo ships are loading tanks and other equipment near the East Coast, Texas and California. Aircraft carriers are steaming to the region, with four expected there by the second week in February, Pentagon officials said.

"I think the main [military] capability will be in place by the third week of February," said William Arkin, a former Army intelligence officer and defense analyst. "If we're not at war by March 15, I'd be stunned."

Loren Thompson, a defense analyst at the Lexington Institute, agreed that with most of the force in the area by that time, "The last week in February would be the most likely time to move."

Retired Army Lt. Col. Ralph Peters, a former military planner, said top commanders would likely be given "a number of dates" or "windows" when they could execute a presidential order to attack.

Peters said bowing to political sensitivities in Europe and the Mideast, a U.S.-led invasion would probably wait until after the hajj, the Muslim pilgrimage.

Some U.S. officials note that with so many charter aircraft and travelers heading to Saudi Arabia, safety concerns might preclude an invasion until a few days after the pilgrimage is over.

A growing force

About 90,000 U.S. troops are in the gulf region, a figure that could increase to nearly 180,000 in the coming weeks and reach perhaps 250,000. Some units expected to take part in an attack - including the 4th Infantry Division from Fort Hood, Texas, and a brigade of the 82nd Airborne Division at Fort Bragg, N.C. - have yet to leave the United States.

In Germany, a weeklong computer simulation that tests plans for a war in Iraq will wrap up next week. The war game, "Victory Scrimmage," includes commanders of several units, such as the Army's 101st Air Assault Division and the 1st Marine Expeditionary Force, that are expected to take part in an attack.

Also, at a military base in southern Hungary, about 100 Iraqi opposition figures who had been living in the United States will begin training next week to work with U.S. forces as translators, guides and military police. Up to several thousand more opposition figures are expected to travel to the Taszar base from Europe and the Middle East for similar training during February, opposition officials said.

Pentagon officials and analysts said the outline of an Iraq invasion plan will combine the speed and airborne attacks of the 1989 Panama invasion with the armored punch of the 1991 Persian Gulf war and the precision bombing of the 2001 Afghanistan campaign.

From many directions

Officials say that unlike the 38 days of bombing that preceded the ground war in 1991, the air and ground attacks this time will be nearly simultaneous rather than sequential. The airstrikes, aided by accurate bombs guided by global positioning systems and lasers, could be over in less than a week. The air attacks foreseen by planners would pinpoint headquarters and communications facilities, suspected chemical and biological storage sites, and radar systems.

Plans call for the U.S.-led forces to surge into the country from many directions - Kuwait, Turkey, Jordan and Saudi Arabia - rather than just the southern route from Saudi Arabia taken by U.S. troops in 1991.