A combination of military, climatic and cultural factors make February the optimum month for any offensive attack by U.S. and allied forces against Iraqi troops occupying Kuwait, according to a senior U.S. military planner involved in the Persian Gulf deployment.

Although the United States won approval yesterday from the U.N. Security Council for a resolution authorizing use of force against Iraqi troops sometime after Jan. 15, U.S. and allied political leaders have not authorized such an attack or decided on its exact timing. The official said that waiting until February would, from a military point of view, provide enough time for the additional troops ordered to the Middle East by President Bush earlier this month to get into place and become accustomed to the climate and terrain of the Saudi Arabian desert.

To wait much longer than that, the official added, would complicate any military operation by running into foul spring weather and the start in March of Islamic religious holidays.

The official, who spoke on condition that he not be identified, underscored the importance of waiting for the deployment of the additional forces ordered by Bush, saying they are needed to provide sufficient "combat power . . . to do the job." Although Arab and other allied forces are expected to join the United States in any offensive campaign against Iraq, the official said U.S. military officers were reluctant to rely on them.

"I would hate to construct a war plan that depended on all those other countries . . . and faced some possible failure" with U.S. soldiers at risk, he said. "You have to have enough Americans there to do the job, and I think that's what our plan is."

Since U.S. deployments began following Iraq's Aug. 2 invasion of Kuwait, the possibility of a U.S. offensive attack, and the optimum timing for such an offensive, have been the subject of widespread public speculation. Many of the U.S. government's comments have been calculated to keep Iraqi President Saddam Hussein off balance and convince him of U.S. resolve, and the likelihood that his forces face destruction if they do not voluntarily withdraw.

As administration officials evolve a strategy for dealing with Iraq that combines political, diplomatic and psychological pressures, military planning for offensive and defensive military options has continued by senior officers on the Pentagon's Crisis Action Team for the Middle East inside the highly restricted quarters of the National Military Command Center.

Each morning, Gen. Colin L. Powell, chairman of the Joint Chiefs of Staff, and Secretary of Defense Richard B. Cheney are briefed separately on the crisis by senior intelligence and operations officers in a gray-paneled "situation room," with a map at one end showing the estimated 300,000 U.S. and allied troops deployed on Saudi territory.

Other maps, shown on computer screens and easels amid a tangle of special telephones for classified discussions with U.S. field commanders in the Persian Gulf, display the deployment of more than 65,000 U.S. military personnel on nearby naval ships and roughly 450,000 Iraqi troops in Kuwait and southern Iraq.

Diplomatic and military intelligence related to the crisis is funneled into a computer system capable of searching and indexing more than a thousand pages of data in a few seconds. A television screen built into a wall displays broadcasts by Cable News Network "100 percent of the time," one official explained, "because sometimes you'll get a tip-off from them that we didn't have from somewhere else."

Although prospects for a military clash have seemed to wax and wane over the past few months, the planning official said he "felt from day one . . . that if there was going to be a fight, it would be after the first of January, unless they attacked us."

The official said he figured at the outset that the timing of any U.S. attack would be affected by three things: "Number one, there was an election in November; number two, Christmas was coming; and number three, {the Islamic holy month of} Ramadan . . . begins on St. Patrick's Day, the 17th of March."

In the first three months of the crisis, he said, the United States was loath to start a war because it "didn't have enough force there to pursue it successfully, except from the air." Most of the additional U.S. forces authorized by Bush early this month will not arrive in the region until mid-January, after which they "should have weeks" -- not months -- to get used to the Saudi climate, he said.

"If you take a little ruler out and draw a line in the middle {of this period between mid-January and mid-March}, that's some time in February," the official added. "The disadvantage is that Hussein can read the calendar as well as we can. And so he knows when the major windows of opportunity exist."

But he said military officials believe that "waiting into the summer can put you in the position of trying to conduct military operations during an extremely difficult time of year. It just gets abominably hot. The wind's blowing all the time; the sands are shifting. It would be extremely tough on the equipment."

The Haj, a period of Moslem pilgrimage to holy Saudi cities such as Mecca and Medina beginning in June, "also is a very important period of time," the official said. ". . . I think the Arabs would be very upset if there was a war going on in the vicinity of . . . {these cities} at a time when they were conducting their pilgrimage . . . . So that could make it difficult. Then you have the Saudi summer, and you're back into the same cycle."