What the Gulf War Tells Us About the Future of Conflict
By Stephen Biddle
From International Security, Vol. 21, No. 2 (Fall 1996)
The standard explanations of the Gulf War's outcome are wrong. The orthodox view explains the war's one-sidedness in terms of the Coalition's strengths, especially its advanced technology, which is often held to have destroyed the Iraqis' equipment or broken their will without exposing Coalition forces to extensive close combat on the ground.(1) The main rival explanation emphasizes Iraqi shortcomings, such as their weak morale, poor training and leadership, or numerical inferiority in the theater of war.(2) Both schools appeared within a few months of the cease-fire, and have changed surprisingly little since then.(3) The information base on the war's conduct, however, has changed substantially with the recent appearance of the first detailed official and semi-official independent histories of the war.(4) This new information, combined with the results of counterfactual analysis using new computer simulation techniques, undermines both schools' conclusions.
To account for what is now known, and in particular, for new details on the conduct of the ground campaign, I propose a new explanation based partly on a combination of pieces taken from both camps' arguments - but mostly on a different conception of how technology and skill affected the outcome. That is, I argue that a synergistic interaction between a major skill imbalance and new technology caused the radical outcome of 1991. In the Gulf War, Iraqi errors created opportunities for new Coalition technology to perform at proving-ground effectiveness levels and sweep actively resisting Iraqi Republican Guard units from the battlefield. Without the Iraqis' mistakes to provide openings, however, the outcome would have been far different in spite of the Coalition's technology, and Coalition casualties would likely have reached or exceeded prewar expectations. But without the new weapons, mistakes like the Iraqis' would not have enabled the Coalition to prevail with the historically low losses of the Gulf War. Many previous armies have displayed combat skills no better than Iraq's, but without producing results anything like those of 1991; only a powerful interaction between skill imbalance and new technology can explain the difference.
This new explanation has important policy implications for net assessment, force planning, and the defense budget. Most current net assessment and force planning methodologies focus on the numbers and technical characteristics of the two sides' weapons.(5) By misunderstanding the role of skill in military outcomes, such methods risk serious misjudgment of states' real military power, and major errors in estimates of the forces needed to meet future threats. Similarly, arguments that modernization spending should be protected at the expense of training and readiness accounts overestimate the military value of technology per se, and underestimate the role of skill in determining the effects that any given technology will produce.(6) While it is always better to have both newer weapons and higher skills, choices must often be made, and it would be a mistake to pay for faster modernization by accepting a less skilled military.
More broadly, this new explanation also challenges perhaps the most sweeping legacy of the war: the new orthodoxy that we are embarked upon a "revolution in military affairs." This thesis holds that precision air and missile strikes will dominate future warfare, and that the struggle for information supremacy will replace the breakthrough battle as the decisive issue for success.(7) I argue that this view is based on a fundamental misreading of the war, and that a proper understanding implies a very different pattern for the conflicts of the future.
To make this case, I first specify the outcome to be explained. I next describe the new information sources on which my analysis of this outcome is based. I then outline briefly the main events of the war, with particular emphasis on the ground campaign, and on a case study of a particular ground engagement (the "Battle of 73 Easting"). From this, I identify a number of important discrepancies between the record of the ground fighting and the implications of the main current explanations of the war's outcome. I then develop my alternative theory, and show how it provides a more satisfactory explanation of what we now know of the war's conduct. Finally, I discuss the implications of that alternative for policy and for scholarship in international security affairs.
The War's Military Outcome and its Legacy
While the Gulf War's disappointing political outcome has received much recent attention, my focus is on its military results, and in particular, the Coalition's ability to prevail with a historically low loss rate.
In less than six weeks, 795,000 Coalition troops destroyed a defending Iraqi army of hundreds of thousands, losing only 240 attackers.(8) This loss rate of fewer than one fatality per 3,000 soldiers was less than one tenth of the Israelis' loss rate in either the 1967 Six-Day War or the Bekaa Valley campaign in 1982, less than one twentieth of the Germans' in their blitzkriegs against Poland or France in 1939-40, and about one one-thousandth of the U.S. Marines' in the invasion of Tarawa in 1943.(9)
This unprecedentedly low loss rate came as a major surprise, despite great efforts before the war to predict losses. These efforts attracted many of the country's foremost scholars and policy analysts, and exploited the best available net assessment methods. The results were way off. All published results radically overestimated casualties: the best got no closer than a factor of three; the next best missed by a factor of six. The majority were off by more than an order of magnitude; official estimates were reportedly high by at least that much, while some official projections were reportedly off by more than a factor of 200.(10)
This unexpected and historically low loss rate has had important policy consequences. It has made the Gulf War a shaping event for defense planning in the 1990s in much the same way as the painful defeat in Vietnam came to shape U.S. planning in the 1980s. U.S. forces are now sized and structured against a Gulf War yardstick. New doctrines, weapons, and organizations are assessed in simulations of updated Gulf Wars. Acceptable casualty levels are judged against a 1991 benchmark.(11)
Before 1991, most planners expected future land wars to look like updated mid-century armored breakthrough battles, with air and missile forces playing mostly a supporting role by reducing the contestants' ability to push tanks forward into the decisive struggle at the point of attack.(12) Today, this traditional concept has almost disappeared, replaced by the new consensus that we are embarked upon a "revolution in military affairs" in which armored breakthroughs will be a thing of the past, and the struggle for information supremacy will be decisive. This sweeping policy legacy is a direct consequence of the extreme nature of the war's military outcome, and especially of the radically low Coalition loss rate. The reasons for this outcome are thus an important question for scholarship, and are my focus here.
New Sources of Information
My explanation of this outcome draws heavily on two new sources of information on the conduct of the war: the Gulf War Air Power Survey and the 73 Easting Project.(13)
The Gulf War Air Power Survey (GWAPS) is an independent analysis commissioned by the U.S. Air Force and modeled on the post-World War II Strategic Bombing Survey. The GWAPS staff had exceptional access to people and information, and produced a detailed five-volume semi-official history of the air war.
The 73 Easting Project is a collaborative study conducted jointly by the independent Institute for Defense Analyses (IDA), the Defense Advanced Research Projects Agency (DARPA), and the U.S. Army. Its purpose was to develop a data base of unprecedented detail on the conduct of a single battle (the "Battle of 73 Easting"), then to use modern computer simulation technology to represent that data in a "virtual re-creation" of the minute-to-minute activities of each participating tank, armored vehicle, truck, or infantry team.(14) The resulting data provides an important resource in itself. But the unique strength of the 73 Easting analysis is the power that computer simulation provides to conduct controlled experiments by changing key characteristics of the historical event, then re-fighting the simulated battle and observing directly the effects on the putative outcome. This makes it possible to test alternative cause-and-effect hypotheses with especially thorough, systematic counterfactual analysis.(15)
Of course, simulation is not reality; as a counterfactual method, it cannot provide the realism of ex post facto observation of real events. A combination of simulation experimentation, deductive argument, and historical analysis by process tracing, however, compensates for the weakness of individual methods, and helps make the most of the available information base.
Overview of Events
The war began with a massive six-week air campaign. This quickly crippled the Iraqi air defense system and destroyed key elements of the Iraqi command and control network. There followed more than a month of effectively uncontested, round-the-clock pounding of ground targets across Iraq and over the entire depth of the Kuwait Theater of Operations (KTO).
As the air war unfolded, Coalition ground forces secretly redeployed from east to west. By February 23, the Coalition had positioned two corps on the Iraqis' extreme right flank. The Iraqis were disposed with 26 conscript infantry divisions deployed forward in a prepared defensive belt. Behind them were 9 higher quality Army mechanized divisions, with 8 elite Republican Guard divisions located well to the rear.(16)
The Coalition ground invasion began on the morning of February 24, when lead elements of two U.S. Marine divisions entered the Iraqi defensive belt near the coastal highway. The main effort, however, was on the far left, where the Coalition VII and XVIII Corps soon followed with a massive single envelopment of the Iraqi forward defenses. This "left hook" quickly collapsed the right wing of the Iraqi defensive belt, and opened a clear path across the Iraqi rear toward the Republican Guard.
Progress was rapid. Iraqi conscript infantry offered little resistance and surrendered in large numbers as Coalition forces overran the forward defenses. By February 26, Kuwait City had been reached, and three heavy divisions of the Coalition VII Corps were massed for a direct assault on the Republican Guard.
Beginning on February 26, VII Corps drove through the Guard from west to east. Unlike the infantry at the border, however, the Guard fought back. By then the surviving Iraqis in the KTO were attempting to withdraw via Basra; perhaps three Guard and another three Army heavy divisions had been redeployed into blocking positions in an attempt to keep their retreat route open.(17) These units were in prepared defenses on familiar terrain, and the result was the heaviest fighting of the campaign as they met the Coalition's heaviest forces head on.
For some 41 hours, a series of battles was fought as VII Corps overran the Iraqi blocking force. Initial contact was made by the U.S. 2nd Armored Cavalry Regiment (ACR), which struck the Iraqi Tawakalna division on a stretch of mostly featureless desert near a map reference line called "73 Easting"; the ensuing engagement thus became known as the "Battle of 73 Easting." Advancing through a heavy sandstorm, the U.S. regiment was ordered to find the enemy, defeat any forward covering forces, determine the position and extent of the main defenses, and fix them in position for assault by the heavier forces advancing behind them. About 4 p.m. on the afternoon of February 26, the regiment's lead troop, under the command of Captain H.R. McMaster, made contact with the main Iraqi position.(18) Launching an immediate assault, McMaster's troop of 9 M1 tanks and 12 M3 Bradleys subsequently destroyed the entire defensive belt in front of them, hitting 37 Iraqi T-72s and 32 other armored vehicles in about 40 minutes. The adjoining troops immediately followed suit. Before stopping to regroup at around 5 p.m., this nominal scouting mission by three U.S. cavalry troops had overrun and wiped out an entire Republican Guard brigade. Subsequent Iraqi counterattacks were beaten off with heavy losses, leaving a total of 113 Iraqi armored vehicles destroyed at the cost of one U.S. Bradley lost and one crew member killed by Iraqi fire (with a second vehicle loss attributed to fratricide). Some 600 Iraqi casualties were removed from the battlefield.(19)
The other actions followed a similar pattern. The largest of these, the Battle of Medina Ridge, pitted the 2nd brigade of the U.S. 1st Armored against the 2nd brigade of the Medina Luminous division. In 40 minutes of fighting, the U.S. brigade annihilated the Iraqi armor in place, took 55 Iraqis prisoner, and killed another 340. No U.S. casualties were suffered.(20) At Objective Norfolk, two battalions of the U.S. 1st Infantry division destroyed more than 100 armored vehicles of the Iraqi Tawakalna and 12th Armored divisions with the loss of two U.S. Bradleys.(21) In the Battle for the Wadi Al Batin, a battalion of the U.S. 3rd Armored division wiped out an Iraqi brigade, killing more than 160 armored vehicles while losing less than a half dozen of its own.(22)
By the morning of February 27, the Iraqi blocking force had been effectively wiped out. In all, VII Corps destroyed as many as 1,350 Iraqi tanks, 1,224 armored troop carriers, 285 artillery pieces, 105 air defense systems and 1,229 trucks. VII Corps itself, by contrast, lost no more than 36 armored vehicles to enemy fire, and suffered a total of only 47 dead and 192 wounded.(23)
What caused this result? The orthodox explanation focuses on Coalition strengths, and especially its superior technology. It holds that new surveillance, air defense suppression, stealth, and precision guidance systems gave Coalition aircraft total command of the skies and radical new lethality against Iraqi ground forces. This in turn enabled the Coalition to destroy the Iraqis' equipment and morale in a six-week air campaign without exposing itself to extensive close combat on the ground.(24) Some members of this school, however, emphasize the Coalition's advanced ground-force technology, such as the thermal sights, compound armor, and depleted uranium (DU) ammunition of the U.S. M1A1 tank, arguing that these enabled Coalition ground forces to strike with virtual immunity from well beyond the effective range of the out-gunned, out-armored Iraqi defenders.(25) Others hold that the Coalition's maneuver warfare concepts (aided significantly by new navigation and communications technologies) enabled it to outflank a static Iraqi defense via sweeping maneuvers conducted over trackless desert, thus ejecting the Iraqis from Kuwait without requiring a costly frontal assault.(26)
On the other hand, some critics have argued that Iraqi shortcomings, not Coalition strengths, were the main reason for the war's one-sidedness. In particular, some have argued that Coalition losses were so low because an unmotivated, dispirited Iraqi army simply did not fight back. As John Mueller recently put it, "The Americans gave a war and no one showed up." A related argument holds that the Iraqis were militarily incompetent, or hopelessly outnumbered.(27) If so, then the Gulf War was less a revolution than merely the "mother of all military anomalies."(28)
In fact, both schools are wrong. To show why, it will be useful to decompose these arguments into their main component pieces. I begin by assessing each component individually, after which I address simple combinations thereof.(29)
The components of the "Coalition strengths" school are Coalition air technology, ground technology, and strategy.
AIR TECHNOLOGY. For new air technology to have caused an unprecedentedly low Coalition loss rate by destroying the Iraqis' equipment or morale before the ground war is to imply that the number of surviving, willing Iraqi weapons must also have been unprecedentedly low by February 24.(30) This was not so. The Iraqi armor force that survived the air campaign was still very large by historical standards, and many of these survivors fought back when attacked by Coalition ground forces.
It is now known that about 2000 Iraqi tanks and 2100 other armored vehicles survived the air campaign and were potentially available to resist the Coalition ground attack on February 24. Equipment attrition during the air campaign was highly variable. While some units suffered nearly 100 percent tank losses, others were virtually untouched. Overall, Iraqi tank attrition averaged about 48 percent, armored troop carrier losses were about 30 percent, and artillery losses were just under 60 percent. These were not uniformly distributed, however. In particular, the Republican Guard was significantly less hard-hit than the infantry and Army heavy divisions nearer the border - Guard tank losses, for example, came to less than 24 percent of their prewar KTO strength.(31)
Some of the surviving vehicles' crews surrendered without fighting, or after only token resistance, but others fought back. While the conscript infantry at the border lacked the will to fight (and may never have had it), the Republican Guard and at least some Army heavy divisions tried to resist the Coalition ground attack.
At 73 Easting, for example, 2nd ACR crews reported large volumes of small arms fire rattling off their vehicles during the assault, which means that Iraqi troops stayed at their weapons, returning fire, even as U.S. tanks passed within a few hundred meters of their positions (i.e., within small-arms range).(32) In fact, some Republican Guard infantry are known to have remained at their posts, concealed, until U.S. attackers had actually driven through their positions, only then emerging to fire short range antitank rockets at the vehicles from behind.(33) Heavy weapons fire was also received. Although large-caliber hits were rare, multiple Iraqi tank gun rounds were observed falling near U.S. vehicles.(34)
Perhaps most important, the Tawakalna division not only defended itself when attacked, but also counterattacked the 2nd ACR after being driven from its positions. After nightfall the Iraqis struck the northernmost of the three U.S. cavalry troops engaged, attacking in multiple, reinforced company-strength waves, and supported by dismounted infantry.(35) This assault was broken up long before it posed a serious threat. Moreover, even in the Tawakalna there is little evidence to suggest fanatical combat motivation: more than 200 prisoners surrendered themselves after the battle.(36)
Nevertheless, there is no evidence to suggest that the Iraqis gave up without fighting in 73 Easting. On the contrary, the readiness of Republican Guard counterattackers to advance at all under such withering fire is difficult to square with a conclusion that the Guard had lost the will to fight. The Tawakalna had ample opportunity to surrender or escape if it wished. Iraqi conscripts at the border had given up in the midst of U.S. assaults without suffering harm; if the Tawakalna had wanted, it too could surely have surrendered without fighting. Alternatively, when the 2nd ACR halted to consolidate, at least one other Iraqi battalion located within earshot of the battle had not yet been engaged; the halt offered this battalion an ideal opportunity to escape or surrender. Yet they stayed, fought, and were destroyed when the advance resumed after midnight. In fact, few prisoners on any part of the field were taken while their equipment was still operable; the great majority of those who surrendered did so only after the battle was over, when the Iraqis' armor had been destroyed and some 600 casualties had been suffered.(37)
Nor had the vehicles' crews deserted prior to the battle. The Tawakalna had moved on February 24 from its pre-invasion locations to occupy the blocking position from which it fought on February 26.(38) Vehicles lacking crews would not have been able to move and thus would not have been present on the 73 Easting battlefield. In fact, the entire Iraqi blocking force that opposed the VII Corps advance had redeployed into its battle positions only a few days before its destruction.(39) Though the Iraqi forces in the KTO as a whole were undoubtedly well under-strength by the time of the ground attack, the Guard and Army mechanized units that fought the VII Corps on February 26-28 had ample crews to man the equipment the VII Corps destroyed.
While we know more of the details for 73 Easting than for many of the war's battles, what we do know suggests that Iraqi behavior there was broadly representative of Guard and Army heavy divisions elsewhere as well. Reports of small arms fire striking Allied armor, for example, are widely distributed among accounts of the fighting on the 26th, 27th, and 28th, as are reports of Iraqi counterattacks, significant tank gun fire, and artillery action.(40) All suggest that the will to fight at 73 Easting was generally representative of the Iraqi blocking force, and possibly of other Iraqi units as well.
We will never know exactly how many of the Iraqis' surviving tanks fought back. We do know, however, that the great majority of Iraq's armor was concentrated in the higher quality units where Iraqi will to fight was greatest; the conscript infantry that gave up most readily was systematically under-equipped in heavy weapons and especially in armored vehicles.(41)
As a conservative lower bound on the number of actively resisting Iraqi tanks, one might count only those weapons in the remnants of five divisions from the Iraqi blocking force that are known to have resisted the VII Corps advance. These alone likely disposed of at least 600 surviving tanks and an additional 600 other armored vehicles on February 24.(42) A plausible range of active survivors might thus be 600 to 2000 Iraqi tanks, and 600 to 2100 other armored vehicles.
By contrast with these 1200 to 4100 Iraqi armored vehicles, the entire German army in Normandy had fewer than 500 tanks in July 1944. The Iraqi lower bound still had more tanks than the entire Israeli army in 1967. The upper bound had about as many as the entire Egyptian army in 1973.(43) If the Iraqis had inflicted only as many casualties per capita as the Arabs in 1967, the result would still have been radically higher Coalition losses.(44) Their inability to do so is thus hard to explain by pre-invasion losses of materiel or will power as a result of the air campaign.(45)
GROUND TECHNOLOGY. Could the Coalition's combination of thermal sights, new armor, stabilized 120 mm guns, and depleted uranium ammunition explain unprecedentedly low Coalition losses? If so, this would imply that friendly forces in close combat without these technologies ought to have fared significantly worse than those equipped with them.
This was not so. Coalition ground force technology varied widely, but losses did not. The two U.S. Marine divisions, for example, were equipped mainly with 1960s-era M60A1 tanks with neither the thermal sights, 120 mm guns, DU ammunition, nor composite armor of the Army's M1A1s, yet the Marines suffered fewer tank losses than the Army against opposition that included Iraqi heavy divisions which fought back when attacked.(46) In fact, some of the Marines' heaviest fighting was by wheeled, thin-skinned, light armored vehicles (LAVs) such as those which defended against the Iraqi counterattack at the Burqan oil field.(47) The Army itself deployed thousands of lightly armored M2 and M3 Bradleys, and the British committed hundreds of similarly light Warrior troop carriers, all of which engaged in extensive close combat yet suffered very few losses.(48)
Second, a ground technology explanation implies that other battles between similarly equipped opponents should produce roughly similar results. Yet at the Army's National Training Center in the Mohave Desert, literally hundreds of battles have been fought between M1A1-equipped U.S. Army units and (simulated) T72-equipped OPFOR (or "opposition force") opponents, and the T72-equipped OPFOR almost always wins.(49)
COALITION STRATEGY. Others have argued that the Coalition's left hook strategy created the low loss rate by outflanking the Iraqis, forcing them to fight a war of maneuver for which they were ill-prepared.(50) But in fact, the key battles against the Republican Guard took the form of a corps-level frontal assault on a prepared positional defense from precisely the direction the Iraqis had anticipated when they established their blocking positions.(51) Moreover, the entire Marine offensive was a direct, frontal penetration of the Saddam line and the primary battle positions of the Iraqi heavy divisions to its rear.(52) Yet neither the VII Corps nor the Marines suffered heavily as a result.
The components of the "Iraqi weaknesses" school are Iraqi numerical inferiority and poor Iraqi troop skills and morale.
IRAQI NUMERICAL INFERIORITY. Many have argued that Iraqi forces in the KTO were seriously understrength, and thus heavily outnumbered by their Coalition opponents.(53) While the Iraqis' actual manpower will probably never be known, it was surely much lower than initial estimates suggested.(54) As a result, the Coalition clearly outnumbered them in the theater overall. In principle, this might explain radically low losses in either of two ways. First, a large force-to-force ratio (or preponderance of attackers over defenders) might enable the attacker to overwhelm the defense so quickly as to quash or preempt effective return fire. Second, a low defensive force-to-space ratio (few defenders spread over a large area) might preclude the conduct of a "coherent" defense, denying the defender the benefits of positional warfare.
But while the theater force-to-force and force-to-space ratios may have been very disadvantageous for the Iraqis, the local imbalances in many of the key battles were much less so. In many important engagements the Iraqis enjoyed favorable local force ratios, yet still failed to inflict heavier losses. If either of these two mechanisms had been a powerful cause, it should have showed up here in heavier Coalition losses, but this was not so.(55)
At Medina Ridge, for example, a Republican Guard brigade conducted a prepared positional defense on a frontage of under 10 kilometers against an attack of roughly equal size.(56) Standard Western defensive frontages for brigade-size units are about 10-20 kilometers (or up to twice the Medina's), and parity is normally considered a very disadvantageous force-to-force ratio for an attack.(57) Yet the Medina brigade was annihilated by frontal assault without inflicting a single Coalition fatality. At 73 Easting, the Tawakalna's 18th brigade conducted a prepared positional defense on a 15-km front and was attacked frontally by a smaller force, yet the defenders destroyed only one of the attackers' 68 armored vehicles before losing essentially all of their own. If high local force-to-space and low local force-to-force ratios could still produce such low Coalition losses, then it is far from clear that numerical imbalance provides an adequate explanation.(58)
IRAQI TROOP SKILLS AND MORALE. The other element of the "Iraqi shortcomings" argument is that Iraqi soldiers' skills and morale were very weak, while the Coalition's were very strong.(59) Iraqi morale was clearly much weaker, and they made many important errors in handling their forces. The Coalition's people were clearly superior soldiers. In fact, Iraqi mistakes are a necessary element of my explanation, as I argue in more detail below. But they are only a part of the story, and cannot explain the result by themselves.
To explain a historically unprecedented outcome this way is to imply that no prior war could have seen a skill imbalance as great. The Coalition's Gulf War loss rate was lower by at least a factor of ten than the Israelis' in the Six-Day War, or the British against the Italians in North Africa in 1941, or the Royal Marines against Argentine Army conscripts in 1982.(60) Of course, it is hard to measure skill differentials precisely.(61) But it is far from obvious that the difference between Coalition and Iraqi skills in 1991 dwarfs the imbalance between any of these armies. In each case the attacker enjoyed a major advantage in personnel quality and motivation, yet in no case were the attacker's losses anywhere near as low as during the Gulf War. Given this, it seems more likely that skill and motivation comprise only a part of a much larger picture. The challenge for analysis is to understand the complete picture, and how its pieces fit together.
SIMPLE COMBINATIONS OF CAUSES
How might such a larger picture fit together? One possibility is a simple linear combination of the causes described above. While there are too many possible combinations to address each individually, two general points should be made.
First, while much of the literature cites multiple causes, the analysis of causal mechanisms (or how the cited factors brought about the observed outcome) is almost always strictly univariate. That is, individual causes (and their effects) are described independently, providing no reason to expect the combination of several causes to yield more than just the sum of the parts taken individually.
Second, to explain the Gulf War, the sum of the parts must be large indeed. The Coalition loss rate was far lower than even very one-sided historical battles. To explain an order-of-magnitude difference in loss rates between 1991 and 1967 or 1982, for example, by a linear combination of contributing causes thus requires either a long list of contributors, or that at least some be very powerful.
The available information, however, provides little evidence to support such a conclusion. Each of the existing univariate explanations poses serious inconsistencies with the historical record. To explain, for example, the difference in attacker loss rate between the 1991 and 1967 Mideast wars by reference to the linear combination of 1991 air-induced attrition (or non-resistance); 1991 ground technology; skill or combat motivation; and Coalition numerical superiority is to imply that the latter three effects account for more than a factor of four in Iraqi combat performance relative to the Arabs' in 1967,(62) even though Coalition ground technology varied widely across the theater of war; the Arab-Israeli skill/motivation imbalance in 1967 was arguably as large as that of 1991 or nearly so; and many of the key engagements in 1991 were fought without meaningful local numerical advantages.
While such a possibility cannot be entirely ruled out, it is at least not obvious that the effects cited offer the necessary explanatory power in light of all that is now known. The case for an adequate explanation by simple linear combinations of causes is thus far from made.
But while an adequate linear combination may be hard to assemble given the limited strength of the component univariate pieces, nonlinear synergistic effects might enable a stronger explanation to be drawn from the same components, since nonlinear explanations permit the multivariate whole to be greater than the sum of its parts. An adequate nonlinear multivariate explanation, however, requires a new causal mechanism, and a demonstration that this mechanism is consistent with the observed events of the war.