When the Cold War ended, the US reduced its armed forces and recast its defense strategy into a regional conflict mold. Unfortunately, the main vehicle by which it did so was the Bottom-Up Review of 1993.

The BUR, as it came to be known, is often depicted as a thoughtful reevaluation of strategy. In fact, it was a fiscal exercise to find operational concepts that would fit the blind budget cuts made several months earlier by the Clinton Administration.

After several miscues, the BUR declared that US forces ought to be ready to fight and win two major regional conflicts, "almost simultaneously." ("Almost," we learned later, meant a separation of 45 days.) However, the BUR did not provide enough forces or enough funding to execute a two-MRC strategy.

Focused as it was on the budget, the BUR took insufficient note of the changing nature of warfare or of the nation's operational experience in the most recent regional conflict, the Persian Gulf War of 1991.

The two-MRC strategy is stiffly traditional. In the initial phase, US forces, chiefly airpower, seek to halt an invasion. That done, the air effort slackens during an extended buildup phase for US land, sea, and air forces. The final phase is a large-scale air-land counteroffensive to defeat the enemy.

The Gulf War followed a different pattern. The 43-day air campaign not only halted the Iraqis but also reduced their military effectiveness so much that the US ground offensive lasted only 100 hours. Moreover, the Gulf War provided an instructive set piece in the Battle of Khafji.

Two weeks into the war, Iraq was reeling from the constant air attacks and wanted to induce a fight on the ground. To provoke such an exchange, Iraqi armored divisions moved against the lightly defended border town of Khafji in Saudi Arabia. Their hope, apparently, was to lure coalition ground forces back into the strength of the Iraqi defenses.

It didn't work. A Joint STARS surveillance aircraft spotted an armored column moving through the night and vectored two A-10s and an AC-130 gunship onto it. Among them, they destroyed 58 of the 71 vehicles. Airpower continued to hammer the invaders and harried them relentlessly on the way out. One tank brigade, caught in the open, was practically destroyed from the air. A survivor said that all the brigade had endured during 10 years of the Iran-Iraq war did not equal what happened to it in 15 minutes in the desert north of Khafji.

An interesting footnote is that the summer before, a US Central Command exercise, Internal Look, predicted that airpower would not be very effective against Iraqi armored formations.

Prodded by the Air Force, the Pentagon is revisiting assumptions of the BUR and the two-MRC strategy in the course of the Deep Attack/Weapons Mix Study, the Joint Strategy Review, and the Quadrennial Defense Review.

A simulation model called "Tacwar" figures prominently in the argument. "Tacwar" has great influence on joint force planning, and its concepts tend to be reflected in theater war plans.

When the Air Force mounted its challenge to "Tacwar" last year, the model assumed that the enemy's military effectiveness would be reduced by about 20 percent in the first 15 days of the conflict. At that point, "Tacwar" curtailed the air effort until land forces had time to arrive and held back preferred aerial munitions to support the ground counteroffensive.

Part of the problem was that the model--and the joint force planning process--undervalued airpower. For example, "Tacwar" estimated sortie effectiveness at 15 percent, less than the Air Force achieved in Vietnam. Sortie effectiveness in the Gulf War was about 50 percent. In Bosnia-Hercegovina, it was 59 percent. By the model's logic, it took 16 sorties to destroy an armored personnel carrier. "Tacwar," since modified, now figures that three or four sorties will do the job. That's better than the previous estimate, but in reality, the Air Force says it can take out three to four APCs per sortie when using preferred munitions.

Another part of the problem is that joint strategy, geared to dominant surface maneuver, has not kept pace with change. The Napoleonic style of war, characterized by attrition, the clash of force on force, and high casualties, is giving way to new approaches made possible by the combination of information technology, stealth, and long-range precision strike.

The Air Force believes early arriving US forces can achieve more than is now expected of them in the halt phase of a conflict. The objective should be a decisive halt, in which we hold air dominance and in which the enemy no longer has the capability to advance and his strategic options are exhausted.

This, the Air Force says, will be a "culminating point" at which the theater commander has a number of options to further disable the enemy regime, ranging from a ground offensive to continuation of the air campaign.

The sooner US forces can render the enemy ineffective in one regional conflict, the faster they will be ready to swing over to a second conflict, putting new credibility into the national strategy and improving on the difference between "almost simultaneously" and the 45-day gap.