Secretary of Defense Dick Cheney, Chairman of the Joint Chiefs of Staff Gen. Colin Powell, and service leaders say Mr. Aspin's proposal is off track.

Army Chief of Staff Gen. Gordon R. Sullivan predicts that the force Mr. Aspin prescribes would suffer a high rate of casualties in combat and be less likely to achieve decisive victory on the battlefield.

The most picturesque criticism, however, came from Gen. Merrill A. McPeak, Air Force Chief of Staff, who said that Mr. Aspin got his numbers wrong and that his Desert Storm Equivalent would be more accurately termed "Desert Drizzle." The force structure options suggested by Mr. Aspin and his staff "are a recipe for military disaster," General McPeak said.

That illustrates the intensity of the battle under way in Washington power centers about the size and structure of US armed forces in the late 1990s. Participants include not only the Pentagon, the Administration, and Congress but also legions of private sector analysts and special interest groups.

All manner of proposals have been advanced, but serious attention concentrates on two of them--the Pentagon's Base Force projection and Mr. Aspin's "Option C," drawn up by the House Armed Services Committee staff.

Option C would cut the Pentagon's stripped-down Base Force by another three Army divisions, eight Air Force wings, and 120 Navy ships. It also prescribes a further reduction of 233,000 military personnel, 93 percent of it to come from the active-duty forces.

Pentagon leaders argue that it would be a mistake to abandon the Base Force structure, which is geared directly to the revised defense strategy adopted two years ago. The Base Force, they point out, reduces military strength by 779,000 from its peak in 1987 and would eliminate a fourth of the Army's active-duty divisions and almost a third of the Air Force's active-duty fighter wings that existed in 1991.

Mr. Aspin brackets his Option C with alternative force proposals--several of them considerably more extreme--made by others. Beyond the defense community, his position is widely perceived as moderate and middle-of-the-road. The House Budget Committee, for example, used Option C as the basis for its defense budget resolution in March.

Behind the Arguments

The various challenges to the Base Force, including Mr. Aspin's Option C, derive mainly from three considerations.

Money. The federal deficit for 1992 is $425 billion. Congress is unwilling to curb entitlement programs, which have been the main growth factor in federal spending for the past 20 years. The Administration has agreed to cut the defense budget by thirty percent between 1990 and 1997, but Congress is demanding a larger "peace dividend."

Mr. Aspin estimates that his Option C would save an additional $48 billion over five years. He points out that others call for larger reductions, citing the example of Rep. Ronald V. Dellums (D-Calif.), who urges a $400 billion defense cut spread over four years.

Sen. Sam Nunn (D-Ga.), Chairman of the Senate Armed Services Committee, disagrees with Mr. Aspin about near-term reductions but says he believes the Base Force can be cut and that a further $30 billion to $35 billion can be saved over the next five years.

Force mix. The Guard-Reserve issue is a political nuke. So far, most of the defense reductions have been made in the active-duty force, with Congress blocking attempts by the Pentagon to make corresponding reductions in the National Guard and Reserve.

In March, Secretary Cheney sent Congress a list of 830 Guard and Reserve units he proposes to reduce or inactivate. Most of the reductions would be in the Army Reserve component, which is at present larger than the active-duty Army.

Most of the alternative force proposals, including Option C, strike hardest at the active-duty force. In a remarkable position paper published in February, the National Guard Association declared that "the existing Total Force Policy and the emerging Base Force policy are competing strategies."

Challenging the Pentagon head-on, the Guard Association says that the Army should have 10 active-duty divisions and ten National Guard division equivalents, rather than 12 active-duty divisions, six reserve divisions, and two cadre divisions as projected for the Base Force.

The Guard Association says the Pentagon has slim chance of getting the budgets it has requested and could have more defense for its money with a richer mix of reserve components at "approximately 25 percent of the recurring costs of active forces at the same level of organization."

Asked about that by the Senate, General Powell said that such a percentage might apply to manpower-intensive forces but that more sophisticated reserve component units cost around eighty percent as much as active-duty forces. He said he did not need any more Guard divisions in the force structure.

Estimates of the requirement. Mr. Aspin's main claim is that his estimate of force requirements is better than the Pentagon's, which he derides as "defense by subtraction," calculated by obsolete "top-down" methodology, leading to "less of the same."

He presents his alternative in great detail, complete with charts, tables, footnotes, and the kind of catchy phrases that are something of an Aspin trademark.

His working paper postulates four options, but three of them are obvious throwaways. His keeper is Option C. "Compared to the Pentagon's proposed Base Force," Mr. Aspin says, "Force C would put proportionately more emphasis on naval power projection, Marine Corps expeditionary forces, and our National Guard and Reserve Forces."

The Base Force

The basic point of reference for all of the arguments and alternatives is the Base Force. Even Mr. Aspin, who makes much of having calculated Option C from the ground up, repeatedly uses the Base Force as his standard of comparison.

Two years ago, on the eve of the Persian Gulf War and before the collapse of the Soviet Union, the Pentagon switched to a new defense strategy, built around smaller forces, fewer deployments overseas, and the assumption that the primary threats would be regional rather than global.

It subsequently devised a Base Force structure to implement that strategy. The drawdown and realignment of US forces was accelerated, falling toward Base Force levels by the mid-1990s.

"The force structure options suggested by Mr. Aspin and his staff "are a recipe for military disaster," said General McPeak.

As a force-sizing tool, "not a blueprint for a new command structure," the Base Force is subdivided into four conceptual force packages (Strategic, Atlantic, Pacific, and Contingency forces) and four supporting capabilities (space, transportation, reconstitution, and research and development). Overall, the Base Force would be some 25 percent smaller than US forces of the 1980s.

Critics of the Base Force say it is obsolete because the underlying concepts were developed before the fall of the Soviet Union. General Powell rejected that charge under heavy grilling by the Senate Armed Services Committee in March.

Sen. Carl Levin (D-Mich.) was foremost among those doubting that the Department of Defense in 1990 was actually basing its plans on Soviet disintegration, which did not occur for another year.

General Powell offered to show the senators two-year-old charts that anticipated a 50 percent reduction in Soviet armed forces and a 40 percent drop in the size of the Soviet military-industrial complex. He added that while the Soviet Union may have disappeared since then, the aggregate of forces in that part of the world has not yet dropped by the 50 percent in the planning base.

(The public record supports General Powell's claim. The 1991 Joint Military Net Assessment, published five months before the Moscow coup that set up the demise of the Soviet Union, clearly stated that global war was no longer the planning focus of US strategy and that potential conflict in Europe had been downgraded to the status of a major regional contingency.)

General Powell cited the various requirements for US military capability. "When you add those--a Desert Storm Equivalent and forces deployed forward, in Korea and in Europe, and with some residual ability in the United States to still influence events--add it up and I get the Base Force," he told the Senate.

He acknowledged that some adjustments to the Base Force may be possible in time but says that premature alterations would be a critical mistake.

"My concern is that people are trying to shove us below the Base Force now, and the only reason for doing that is to increase the rate of drawdown to a lower number," he told the Senate. "That is where you run into disasterville."

Aspin's New Math

The person General Powell would most like to convince is Mr. Aspin, who is defending his position aggressively. To a considerable extent, Mr. Aspin bases his challenge on methodology, claiming that his differs from the Defense Department's in two important respects.

First, he says he used a "bottom-up" approach to identify "building blocks" of requirements from scratch. "Top-down force planning--what they are practicing in the Pentagon as they take successive cuts out of the budget--will leave us with a smaller version of the force we built for the cold war."

Second, Mr. Aspin says, Option C is "threat based," meaning it is tightly structured to meet clear and specific threats. "In this era of belt tightening, our citizens understandably may be reluctant to pay for defense unless there is a clear linkage between the forces and the threats those forces are designed to deal with," he says.

Mr. Aspin lists six situations "for which Americans might want military forces" in the 1990s: countering regional aggressors, combating the spread of nuclear and other mass terror weapons, fighting terrorism, restricting drug trafficking, keeping the peace, and assisting civilians.

From there on, Mr. Aspin's figuring is influenced strongly by the Persian Gulf War of 1991. For his "unit of account" in sizing threats, he adopts the "Iraq Equivalent" score developed by the Congressional Budget Office. Prewar Iraq, rated at 1.0, is the basis for the scale. North Korea, for example, rates 0.6 in land forces, 90.0 in seapower, and 2.6 in airpower.

The CBO scale considers nothing except force size and composition. In other words, it is a straight bean count, which Mr. Aspin acknowledges (although not exactly in those words).

Recognizing the need for qualitative measures, Mr. Aspin chooses the "Desert Storm Equivalent"-sized to deal with one Iraq Equivalent of threat--as the major building block for his Force C.

The basic Desert Storm Equivalent, "the force that mattered" in the Gulf War, "has six heavy divisions, an air-transportable, early arriving light division, one Marine division on land and an excess of one brigade at sea, 24 Air Force fighter squadrons, 70 heavy bombers, and two early arriving carrier battle groups, building up over time to four carrier battle groups including surface combatants," Mr. Aspin says.

Option C, according to Mr. Aspin, would provide for one Desert Storm equivalent, a Korea-sized contingency, a Panama-sized contingency, humanitarian missions, airlift, sealift, and a base for rotation of forces between the United States and overseas.

Weinbergerization and Drizzle

Mr. Aspin's numbers drew a candid response from Air Force Chief McPeak, who said that "twenty-four squadrons is not the force we employed in the Gulf War. During Desert Storm, the US Air Force had 33 fighter squadrons of all types in theater. Our allies provided another eight FWE [fighter wing equivalents] or 24 squadrons to the effort, meaning that a 'Desert Storm Equivalent' is about57 total land-based fighter squadrons."

Noting the several force-structure alternatives devised by the House Armed Services Committee, General McPeak said, "My guess is that no one responsible for the outcome would ever sign up to those options as meeting the stated goals."

Referring to Mr. Aspin's declaration that "in the post­cold war era we will not plan on fighting long wars with high casualties," General McPeak said, "In my judgment, the options proposed would result in exactly that outcome; that is, sustained combat and higher casualties."

General McPeak's criticism figured prominently in an April 3 statement from Mr. Aspin accusing the Pentagon of "Weinbergerizing" the defense debate.

"Cap [former Secretary of Defense Caspar Weinberger] was quick to predict utter ruin if Congress deviated from his program," Mr. Aspin said. "That sort of thing cost Cap dearly. Eventually he 'Weinbergerized' himself out of the debate. His claims simply weren't credible."

He indicted both Secretary Cheney and General Powell for a revival of Weinbergerization, but bore down with special vigor on General McPeak.

"Another form of Weinbergerization," Mr. Aspin said, is "making claims on the public record that are known to be contradicted in classified information." In that context, he quoted General McPeak as saying that Option C's 24 squadron "Desert Storm Equivalent is not a Desert Storm Equivalent. I call it Desert Drizzle."

Mr. Aspin continued, "I can only conclude that General McPeak has not been reading the Pentagon's own classified scenarios for a renewed conflict in southwest Asia. If he had, I hope a respect for the facts would make him change his tune. I can't go into detail here, but the classified documents say McPeak is wrong and the Desert Storm Equivalent could do the job."

Leaks and Scenarios

The classified scenarios invoked by Mr. Aspin were apparently those from a planning paper leaked by a disgruntled Pentagon staffer to the New York Times and summarized in that newspaper Feb. 17. The document was reported to list seven "illustrative" scenarios, including one in which Iraq invades Kuwait and Saudi Arabia and another in which Russia attacks Poland with help from Belarus (formerly Byelorussia).

Mr. Aspin sees the scenarios as vindication of his threat-based planning principle as well as confirming the assumptions of Option C.

"The Pentagon is using threat analysis internally to shape future budgets while claiming publicly that it will not work," he said. "We say it will. If the seven scenarios written as Fiscal Year 1994 budget guidance were part of the public debate, I suspect it would thoroughly validate the Desert Storm Equivalent, the basic building block in my force options."

When the Senate Armed Services Committee asked General Powell in March about the New York Times scenarios, he depicted them as a war-gaming exercise run to help structure the next year's defense planning guidance.

"The Base Force, I assure you, was not designed on the basis of some scenario that said we're going to have a major war up in the northeast corner of Europe," he added.

As for the Pentagon's approach to force planning, General Powell said, "I think we did do it from the bottom up, but I can't ignore the top down. I live in a top-down world. I'm not writing on a blank piece of paper."

For example, he said, "I see proposals that say 'take out another 200,000 reservists, 16,000 reservists, when I can't get the Congress to take out the reserve structure that we have been asking for for the last three and a half years."

The War-Planner's Art

Mr. Aspin paints a sharp line between his methods and those he attributes to the Pentagon. In fact, however, threat-based, bottom-up calculations are standard techniques for military planners.

They routinely use these methods-and in more detail than shows in Mr. Aspin's working papers-to run a wide variety of simulations, war games, and force-sizing exercises. Despite the appearance of mathematical precision, such calculations are no more than data-based estimates.

Actual combat seldom plays out the way it was modeled. The Gulf War, for example, took a third more fighter forces than calculated in the planning guidance for a "major regional contingency."

How well the Desert Storm Equivalent can predict requirements for a different conflict is questionable. The war was shaped by a number of factors: international support for the coalition, Saddam Hussein's tactical blundering, uncontested deployment of forces to the battle theater, the five-month interlude before combat, and more.

A change in situational variables for the next conflict could redefine the requirements rather severely.

As many in the defense community see it, Mr. Aspin has cut his estimates too fine and gives up a great many troops, divisions, ships, and air wings for a comparatively modest financial yield. His projected five-year savings, $48 billion, amount to a figure only 3.4 percent less than the Administration is requesting for the Base Force program.

For all of that, Mr. Aspin's force-structure options, coming from the chairman of the House Armed Services Committee, carry weight on Capitol Hill.

Sometime in the next few months, Senator Nunn, the most credible voice in Congress in defense matters, will almost certainly elaborate on his views.