WHETHER OR not U.S. forces are ultimately drawn into battle in the Persian Gulf, their leaders in the Pentagon are already locked in a bloodless but fierce engagement: the fight for budget dollars.

Even those who support the American military involvement in the Gulf are having difficulty understanding the rationale behind the size and composition of the force structure being deployed to the region. Unfortunately that deployment seems driven more by uncoming budget battles on Capitol Hill than a potential battle against Saddam Hussein. As the Cold War ends and the large standing military is being reduced, the Pentagon seems to be using the Gulf situation to justify keeping the force that was developed to contain the Soviet Union.

Unfortunately, this is not the first time in the post-World War II period that our military structure and tactics have been designed more to protect the service interest than the national interest. In Vietnam, the military leadership made a bad situation worse by Americanizing the war, sending in far too many forces (about 700,000) and using the strategy and tactics (search and destroy and massive bombing), developed to fight the Soviet Union, against a predominantly guerrilla force. The Army also undermined the effectiveness of units in the field by moving its officers rapidly through command and staff assignments to enhance their promotion potential.

Log-rolling also marred the aborted hostage-rescue attempt in Iran in 1980 and the invasion of Grenada in 1983, as each of the military services was given a piece of the action, where only one or two services were needed. Finally the military found it necessary to send 40,000 troops and weapons systems from all our services, including stealth fighters, against Noriega's glorified police force in Panama. History seems to be repeating itself. By mid-January as a result of recommendations from the field commander, Gen. H. Norman Schwarzkopf, the Joint Chiefs of Staff chairman, Gen. Colin L. Powell, and Secretary of Defense Richard B. Cheney, the United States will have over 400,000 troops in the Gulf from all five armed services (yes, even the Coast Guard is there). This is about 100,000 more troops than we had in Europe at any time during the Cold War.

The Army will eventually have eight divisions on the ground in Saudi Arabia, twice as many as it had in Europe. By mid-January, two-thirds of the entire Marine Corps' combat power (two expeditionary forces) will be in Saudi Arabia and the surrounding waters. The Navy will deploy six of its 14 aircraft carrier battle groups, two of its four battleships and one of its two amphibious groups to the Gulf. The Air Force already has fighters from nine of its 24 active tactical air wings (including the stealth) as well as bombers in the area with more to follow.

Even the combat reserves are scheduled to be sent to the Gulf. The reserve lobby recognized that their future funding may be jeopardized if their units do not get involved. Therefore, they put pressure on supporters in Congress to demand that the Pentagon activate the reserve elements (round-out brigades) of the active divisions deployed (never mind that these bridgades may need four to five months training before they are ready).

From a budget-protection perspective, these massive deployments could not have come at a better time. As Cheney noted in a speech to the Conservative Leadership Conference on Nov. 9, the Gulf crisis proves the United States must remain the world's policeman, and the military budget must remain large despite the end of the Cold War.

Prior to our involvement in the Gulf, the president and Congress agreed to cut the size of the active force by 500,000 people over the next five years. In this reduction, the Army would lose six active divisions, the Navy two carrier battle groups and over 100 ships, the Marines some 50,000 or 25 percent of their 190,000 people and the Air Force 11 tactical fighter wings.

However, if the size and composition of the Gulf deployment is the basis on which we must plan our forces for the post-Cold War era, these reductions cannot be made. Supporting a deployed force of about 450,000 people while providing sufficient forces to protect our interests around the world will require an active force of at least 2 million people, the size of our current force (deploying 700,000 people to Vietnam required an active duty force of 3.5 million). Still more serious are the implications of the bureaucratic impulse if actual fighting breaks out. Just as every service wants to be involved in the deployment, will not each want a piece of the real action? If President Bush decides to initiate military action, many observers, such as Sen. Sam Nunn (D-Ga.), feel that it should be predominantly an air campaign directed against military targets in Iraq and against the supply lines of the Iraqi army deep inside Kuwait. To do this, the land-based tactical air assets of the Air Force would be more than sufficient.

But will Schwarzkopf be able to resist the pressures from the Navy to use the 200 fighters and attack planes on its six carriers -- especially since the Navy has moved some of its carriers into the narrow and dangerous waters of the Gulf just to be closer to the action? Will not the Marines want to demonstrate the continuing viability of amphibious warfare by staging an Inchon-style assault on the coast of Kuwait? Can Army officers Schwarzkopf and Powell allow their Army divisions to lay back while the air power carries the day? (Both Powell and Schwarzkopf urged Cheney to fire Air Force Chief of Staff Gen. Michael J. Dugan for arguing that air power would be the deciding factor in the war.) Finally, will we Americanize this war like Vietnam or will we allow the 120,000 ground troops from our European, Arab and Moslem allies to share in the glory (and casualties)?

For whatever reason, Bush has allowed the Gulf buildup to get out of hand. If he is not careful, this nation could be drawn into a conflict that has more to do with preserving service roles and missions than his new world order. To keep this from happening, the president needs to act quickly to reduce drastically the size of his deployment to the Gulf and to change radically its composition. Initiating a rotation policy is a first step, but the president must also make some basic decisions about what force structure is actually suited to the present threat. Specifically, he should leave the Air Force elements intact but cut substantially the size of the other forces. Two Army divisions, two carrier battle groups and one Marine expeditionary force, coupled with the 125,000 troops, 1,000 tanks, 300 planes and 75 ships of our allies, should be more than enough to defend Saudi Arabia and even force Saddam out of Kuwait. But will it be enough to satisfy the non-military needs of the bureaucrats back home?

Lawrence Korb is director of the Center for Public Policy Education at the Brookings Institution and former assistant secretary of defense.