By Michael Vickers

Sunday, April 6, 2003; Page B01

The war with Iraq is not without its ironies. One is that U.S. ground forces are playing a central role in the campaign and have advanced at unprecedented rates -- a feat that stands in stark contrast to the sideline role played by land power in our two previous wars. Yet active Army generals, on background, and retired ones, on the record, have taken the secretary of defense to task for supposedly limiting the size of the ground component during Operation Iraqi Freedom's early phases.

This angst, private and public, is misplaced.

U.S. ground forces have proven vital to rapid, strategic "preclusion" -- taking away options from the Iraqi regime, a key objective of the war's initial phase -- and to fighting with discrimination in cluttered battle spaces, the only ground on which the Iraqi forces have chosen to make their stand. After a brief pause, U.S. forces have advanced to the outskirts of Baghdad, poised for what may be the last and most challenging part of the ground war. There is scant evidence that U.S. ground forces in Iraq are undermanned or that they are performing anything but brilliantly. Supply lines are being secured, supporters of the regime are being killed or captured, and ample reinforcements, should they prove necessary, are flowing into the theater.

The crucial mission of ground forces is likely to be an enduring one that will be undiminished, or even accentuated, by the ongoing revolution in warfare. This truth has not been self-evident in recent years. Ground force malaise began with the war over Kosovo. In that conflict, President Clinton initially renounced the use of ground forces. Air power held the spotlight. Then, in the wake of the Task Force Hawk debacle -- the Army's dilatory and strategically inconsequential deployment of attack helicopters and missile artillery to Albania -- then-Deputy Secretary of Defense John Hamre informed the Army's senior leadership that if the service didn't change, it faced strategic irrelevancy. A major effort was quickly initiated to transform the Army into a much lighter but still lethal force.

Nonetheless, the decline in the stature of ground forces intensified with the unconventional and rapid overthrow of the Taliban and the pursuit of al Qaeda. When the United States needed ground forces in Afghanistan, it turned to the poorly equipped Afghan opposition forces. Assisted by long-range, precision U.S. air power and Special Operations Forces, these local forces decisively defeated an entrenched enemy, casting further doubt on the continued relevance of conventional U.S. ground forces.

The war with Iraq, however, is being waged differently than the wars in Kosovo and Afghanistan. It also differs from how the first Persian Gulf War was fought 12 years ago. Despite having a far more ambitious objective -- regime change versus ejecting Iraqi forces from Kuwait -- the combined ground force used so far is less than a quarter the size of its Desert Storm predecessor, leading more than a few Army officers to suspect that the secretary of defense is hell-bent on proving some new theory of war at the Army's expense.

At the heart of ground force malaise lies the strategic ascendancy of precision air power. The air arm has displaced its ground counterpart as the U.S. military's main killing mechanism. The Republican Guard divisions that constitute the Iraqi regime's primary line of defense are primarily being destroyed by air power.

For the most part, however, air power works through cumulative effects. Enemy command-and-control and field forces are worn down over time. Ground power, on the other hand, achieves its most decisive effects through major "pulses" of action.

There are three such pulses in the war with Iraq: the initial, rapid movement to within 50 miles of Baghdad to strategically preclude the Iraqi regime from taking certain destructive actions, particularly against its own population; the shattering of Republican Guard lines outside Baghdad; and the overthrow of Baathist rule in the urban areas where forces loyal to the regime are hiding. The first was achieved within four days of the war's beginning -- the ground war was even initiated before the principal air campaign had begun. The second pulse, the breakthrough to Baghdad, is underway. And the third, the end of Baathist rule in the capital, could follow soon. Each of these major pulses of action is being greatly facilitated by air power, but ground forces are essential to attaining all of them with speed and discrimination. Rapid collapse of an enemy force is brought about by exploiting battlefield success, which is what highly mobile ground forces are designed to do.

U.S. and coalition forces, up to a point, control timing in this conflict. Though many analysts fret that the war isn't over already, it is up to U.S. commanders to decide when it will be propitious to deliver the final, shattering blow to the collapsing regime in Baghdad. From a political point of view, there might be a cost to delay. The longer the conflict lasts, the greater symbolism of Iraqi defiance and the risk that instability in the Muslim world could spin out of control. In this sense, perhaps, it's good that we have elected to press the attack. But from a military standpoint, whether we batter the Republican Guard from the air for 4 days or 14 or 40 is ultimately up to us. A measure of patience can work to our advantage. That we would break through and destroy the Republican Guard was a foregone conclusion. We are able to hit them relentlessly; they can hardly hit us. We can move at will and attack their flanks and rear; they move only with great danger. They must disperse to avoid our air attack; we can mass our forces to penetrate their stretched and battered lines.

We are in a similar position to choose how and when we will enter Baghdad now that the city's airport has fallen. We may elect to conduct raids to further weaken the regime's hold on power and induce a popular uprising -- facilitating an "inside-out" collapse. Or we may seize and hold key places to depose the regime "from the outside in." Once again, flexibility about timing can be a useful thing.

Land power will play an even more central role after the war, performing what the military calls "stabilizing operations." Only ground forces can ensure the successful political and economic reconstruction of Iraq. A sizable ground force -- Pentagon joint staff estimates are in the range of 45,000 to 60,000 -- will be required.

Since the decapitation effort aimed at Iraq's leadership, the "shock and awe" air campaign and the rapid advance of ground forces to the gates of Baghdad did not immediately cause the collapse of Saddam Hussein's regime, some have argued that the war with Iraq has invalidated the notion that revolutionary changes in warfare are taking place. Yet U.S. capabilities, particularly those in the area of precision air attack, have severely constricted Iraq's strategic options and, in a short period of time they will lead to the one-sided destruction of the Iraqi regime.

America's post-Cold War conflicts all provide evidence that fundamental strategic change is underway. Twelve years ago, during the first Persian Gulf War, only 7 percent of U.S. munitions were precision-guided; today 90 percent are. Thanks to stealth aircraft and cruise missiles, we have been able to attack targets anywhere in the battlefield with impunity.

Yet Iraqi strategic behavior, like that of the Serbs before them, also points to the continued relevance of ground forces. Exploiting this revolution's full strategic effects requires that air and ground forces -- be they U.S. or indigenous opposition forces -- work in tandem. The dominance of long-range precision strike capabilities has already caused and will continue to cause both an "emptying" and a "cluttering" of the battle space -- a dispersal of enemy forces and their search for refuge in places crowded with civilians.

The ability to rapidly exploit the effects of precision air power and carefully choose targets within crowded battle spaces will ensure an important, if less central, combat role for ground forces for decades to come. Since access to forward bases is uncertain, and since the leisure to build up the size of a force in distant theaters cannot be assured, ground forces of the future will need to be far more rapidly deployable than current forces, and ready to operate with greater independence from potentially vulnerable, fixed forward bases. They will need to be just as lethal in close combat as current forces, and will need the ability to strike and move more rapidly and stealthily to avoid being targeted by enemy counterstrikes. But "boots on the ground" will remain a significant feature of the American way of war.

Michael Vickers, a former Special Forces officer and CIA operations officer, is director of Strategic Studies at the Center for Strategic and Budgetary Assessments.