06 November 2006

The True Worth of Air Power

By Robert A. Pape
Foreign Affairs, March/April 2004

For more than a decade, advocates of precision air weapons have argued that wars can be won by selectively taking out an enemy's leaders, its communication systems, and the economic infrastructure of its major cities. Before the Persian Gulf War, Air Force Chief of Staff General Michael Dugan promised to end the war in days by targeting Saddam Hussein directly. Later, in Kosovo, General Michael Short, commander of allied air forces in Europe, ordered air power to "go for the head of the snake." And last year, in the Iraq war, Secretary of Defense Donald Rumsfeld sponsored a "shock and awe" air campaign against the Iraqi leadership. Whether it helps kill enemy leaders, isolate them from their troops, or make them vulnerable to overthrow by local groups, precision air power is advertised as a force that can win wars on its own.

Decapitating the enemy has a seductive logic. It exploits the United States' advantage in precision air power; it promises to win wars in just days, with few casualties among friendly forces and enemy civilians; and it delays committing large numbers of ground troops until they can be welcomed as liberators rather than as conquerors. But decapitation strategies have never been effective, and the advent of precision air weaponry has not made them any more so.

No doubt, precision technology has increased the accuracy of bombing. Today, 70 to 80 percent of guided munitions fall within 10 meters of their targets, even at night, with overcast skies, or in moderate winds. This is a remarkable improvement compared to World War II, when only about 18 percent of U.S. bombs fell within 1,000 feet of their targets, and only 20 percent of British bombs dropped at night fell within 5 miles of theirs.

Yet greater accuracy has not enabled air operations alone to win major wars any more than they did before the precision age. Independent air operations have rarely been decisive. From World War I until the 1980s, they were most effective in support of ground power, serving as the "hammer" to ground power's "anvil," with the anvil usually doing most of the work. Thanks to precision weapons, air power has become a far more effective complement to ground power; the hammer now does much more work for the anvil.

Precision air weapons have fundamentally changed military power, but they have not brought about the revolution often proclaimed by many air power advocates. Despite precision bombing, enemy decapitation has not become "the new American way of war." Rather, precision weaponry has revolutionized contemporary warfare by multiplying the effectiveness of using air and ground power together. The United States, in other words, still wins its wars the old-fashioned way. But with new precision air weapons, it now does so better than ever.

OFF WITH THEIR HEADS?

The strategy of enemy decapitation has inherent shortcomings, which precision technology, for all its advantages, cannot overcome. U.S. forces have tried the strategy on six occasions in the past 16 years, and it either failed or backfired each time.

The tactic proved largely ineffective in Afghanistan in 2001, when the United States dedicated weeks of air strikes to trying to kill Mullah Muhammad Omar and other Taliban leaders. Prior to last year's war, it had also achieved little in Iraq. The United States attacked 235 strategic targets in and near Baghdad in the opening days of the 1991 Gulf War and subsequently about 100 leadership and other targets in the four-day Operation Desert Fox in 1998. Both campaigns failed to kill Saddam or to weaken his control over his troops and the country.

Last year's shock-and-awe campaign in Iraq also yielded disappointing results. Raids against hundreds of targets during the war's early stages failed to kill or topple Saddam. Admittedly, they did help raise confidence in the imminent collapse of his regime and paved the way for the arrival of ground troops, who eventually caught Saddam last December. But late last March, General Richard Myers, the chairman of the Joint Chiefs of Staff, acknowledged that the Pentagon's strategy to knock out Saddam's regime early on using devastating air assaults had proved less effective than expected.

In other instances, decapitation tactics have proved downright counterproductive. The 1986 bombing of Muammar al-Qaddafi's tent by the U.S. Air Force, which missed him but killed his young daughter, probably precipitated the revenge bombing of Pan Am flight 103 that killed 270 civilians. In March 1999, in an attempt to strong-arm Serbian President Slobodan Milosevic into adopting a more forthcoming policy toward ethnic Albanians in Kosovo, the United States launched what was supposed to be a three-day air campaign against 51 targets in and near Belgrade. Not only did these strikes fail to coerce Milosevic, they prompted the Serbian military to kill thousands of Kosovars and expel almost a million from the country.

The development of increasingly precise weaponry has not made decapitation strategies any more viable, for three reasons. First, killing leaders and accurately attacking communications networks depends more on military intelligence than on precision in combat. Without precise intelligence, precise weapons may precisely destroy targets that are not in use. Second, there are generally so few leadership targets that they can be destroyed even without precision weapons. Third, even successful hits may not translate into coercive success. Determining which ones will is a problem of political forecasting -- and an uncommonly difficult one. No current theory can predict whether air power alone can force regimes to change or assure that they will change in the right direction.

Decapitation has failed repeatedly, in other words, and against a variety of enemies, even when U.S. forces benefited from substantial intelligence and extraordinarily sophisticated equipment. Although precision weapons may produce lucky strikes in the future, there is good reason to doubt that decapitation will become a model strategy for the United States any time soon.

HAMMER AND ANVIL

The United States has chalked up a tremendous military record in the precision age. In just over a decade, it has won five major wars -- in Kuwait and Iraq in 1991, in Bosnia in 1995, in Kosovo in 1999, in Afghanistan in 2001, and in Iraq again in 2003 -- at the cost of only about 400 combat fatalities overall. Precision air power played an important role in these victories, not by helping decapitate the enemy, but mainly by helping friendly ground power crush enemy ground forces more efficiently.

Long before the age of precision weapons, the U.S. Air Force used mass air strikes to destroy critical political and economic targets. U.S. bombers flattened factories and other buildings in Germany and Japan and electric-power plants in North Korea and Vietnam with large numbers of "dumb" bombs. Today's precision weapons have not increased the coercive effectiveness of these tactics, which has always been limited, but they have made it possible to destroy similar targets with fewer sorties.

More important, improved bombing accuracy means that the hammer-and-anvil strategy is far more potent today than ever before. Attacking the enemy simultaneously by air and on the ground puts the enemy army in a quandary. If the enemy concentrates its ground forces in large numbers to form thick and overlapping fields of fire, they become vulnerable to air raids. But if it disperses them to avoid air strikes, opposing ground forces can defeat them in detail, mopping them up with few losses.

In the past, the U.S. Air Force would attack enemy ground formations if they presented especially attractive targets, such as road-bound columns of hundreds of vehicles that could be repeatedly strafed from above. Such attacks played a large role in defeating the Germans on the western front in World War II. Today's precision weapons allow air power to destroy massed enemy ground troops more easily, under a variety of conditions, and to attack other smaller, but still important, battlefield targets. Until recently, air power could rarely destroy tanks, trucks, command posts, or bridges used to supply fielded forces; even thousands of bombs aimed at just a handful of these tiny military targets could miss the mark. Now, satellites, advanced reconnaissance aircraft, and other sensors can reliably locate concentrated enemy forces for precision strikes to destroy. Even if enemy ground forces do not move, precision air power can respond quickly to their defensive fire. Today's precision weaponry thus allows air power and ground forces together to defeat enemy ground forces relatively rapidly and with few losses.

Combined power works best when it exploits the tactics commonly used by large mechanized armies in modern warfare, which have not changed with the advent of precision weaponry. Since World War II, attackers in mechanized warfare have usually tried to break through the enemy line and then advance, through the breach, deep into enemy territory. To prevent such breakthroughs, defenders typically seek to build formidable front lines, so that any section that is attacked can hold out until local reserves arrive. If breakthroughs do occur, defenders use mobile reserves to counterattack the exposed flanks of the penetrating spearheads, in order to cut them off (or at least slow them down) while a new defensive line is established.

Air power plays an important role in this situation. It is a significant offensive tool that can thwart defensive strategies in two ways. Air power can help an attacker weaken the enemy's front line by attacking it directly or blocking its access to supplies and possible reinforcements. More important, air power can also assist penetrating spearheads after a breakthrough, by stopping the movement of enemy reserves deeper behind the front and preventing them from redeploying or concentrating against the attackers.

Combining air and ground power continues to be a winning strategy in the precision age. It has played a key role in the United States' spectacular recent victories: its application helped win four wars, and the prospect that it might be used probably was decisive in a fifth.

IRAQ, PART 1

Before the air war began on January 17, 1991, Saddam was highly confident that his army could hold Kuwait. His calculation was simple: the United States, he told April Glaspie, then the U.S. ambassador to Iraq, would not tolerate 10,000 deaths. U.S. leaders also believed that if the toll reached those figures, public support for the war would dwindle, and most analysts estimated that it would take at least that many casualties -- and perhaps even twice that number -- for U.S. troops to win a ground war.

But Saddam was underestimating a critical U.S. asset: overwhelming air superiority, which eventually helped drive his troops out of Kuwait with only 147 U.S. fatalities -- fewer than even the most optimistic prewar estimate. The air power that defeated Iraq was not the bombing of Baghdad that captivated millions of CNN viewers, but the direct pounding of the Iraqi army in Kuwait, which denied Saddam a chance to inflict heavy costs on the coalition ground offensive.

U.S. air power made it impossible for the Iraqis to stop a breakthrough at the front. Direct raids killed 30,000 to 36,000 Iraqi troops and convinced another 100,000, who had been carpet-bombed and were starving, to desert. Those losses created huge holes in the Iraqi ranks and encouraged most of the remaining front-line infantry to surrender without resistance when the ground war began. Penetrating coalition spearheads found breaches in the Iraqi front up to two kilometers wide, which allowed them to advance along four-lane highways deep into the Iraqi rear without encountering significant resistance.

Air power also destroyed a significant number of Iraq's heavy military equipment -- tanks, armored personnel carriers, and artillery -- well ahead of the ground offensive. Studies conducted by the CIA, the Marine Corps, and the Army after the war showed that air power destroyed about 20 percent of Iraq's heavy military equipment and caused more to be abandoned by Iraqi troops once they realized the equipment was being targeted. Overall, some 9,500 precision-guided munitions destroyed about 2,500 pieces of Iraq's heavy military equipment. This is not a perfect score, but new-generation weapons were considerably more effective than "dumb" bombs would have been against similar targets.

Finally, air power prevented Iraq's mobile reserve forces from concentrating or otherwise moving in significant numbers inside the theater, which kept them from filling gaps in the front lines or blocking coalition ground forces that penetrated their lines. The Iraqi troops' mobility was significantly hindered as soon as the coalition gained air superiority; that was demonstrated as early as during the al Khafji battle in late January. In that confrontation, air raids defeated initial battalion-sized assaults by the Iraqis and then attacked without mercy two Iraqi heavy divisions that were detected marshaling for a follow-up attack. During the four-day ground campaign in February, coalition ground forces advanced almost twice as fast as expected, largely because the Iraqi mobile reserves, although still substantial, could not counter-concentrate en masse to oppose the breakthroughs at the front.

BOSNIA, 1995

The combination of air power and ground power also had a potent effect during the Bosnian war: it brought the Serbs to the bargaining table and helped determine the boundaries of the final map negotiated at Dayton. Although not a single bomb fell on Belgrade during this conflict nor was even a senior Bosnian Serb leader killed, U.S. air power was used to great effect in the field. Bombs were dropped on battlefield command posts, military units, and supply bridges in Bosnia, while 100,000 Croat and Bosnian Muslim ground forces attacked the 50,000 troops of the Bosnian Serb army. For the first time, the hammer-and-anvil strategy used U.S. precision air power working alongside local ground forces.

The use of strong coercive pressure began in the summer of 1995, shortly after Bosnian Serbs executed thousands of Bosnian Muslim civilians at Srebrenica. On August 4, some 100,000 Croat troops launched an intense assault on Krajina, a region of Croatia then under Serb military control. They quickly overran the area, causing most of the region's 175,000 Serbs to flee into Serb-held territory in western Bosnia. On September 8, Croat and Bosnian Muslim troops began a combined ground offensive toward the city of Banja Luka, where 350,000 Serbs lived. Within a week, they were just 20 miles from the city, having seized about a third of the Serb territory in Bosnia. The Bosnian Serbs' political leader, Radovan Karadzic, then promptly agreed to comprehensive talks and withdrew heavy weapons from Sarajevo. ("If we have a cessation of hostilities agreement," he said, "it means there is not going to be war in Sarajevo any longer.") The cease-fire went into effect on October 12.

The U.S. air operation Deliberate Force was a critical complement to forces on the ground, largely because it bombed military targets in Bosnia and hindered the Bosnian Serb army's ability to counter-concentrate against the oncoming Muslim-Croat ground offensive. From August 30 to September 14, U.S. air strikes delivered 1,026 bombs against 56 military targets in western Bosnia and near Sarajevo -- less than half the munitions used per day against Saddam's army in the Persian Gulf War, but enough to debilitate the far smaller and less heavily armed Bosnian Serb army.

Americans naturally call attention to the role U.S. air power played in coercing Milosevic to surrender, but it accomplished this result only by helping shift the balance in the ground war. The Dayton boundaries are, almost to the kilometer, the front lines controlled by the Croat and Muslim armies at the moment the peace agreement was signed in the fall of 1995. Top U.S. officials acknowledged that the combined use of air power and ground power helped win the war -- and shape the peace. General Michael Ryan, the commander of allied air forces, observed that "it took both" -- air power "nailed down" the Bosnian Serbs, preventing them from responding to the Muslim-Croat offensive on the ground. Ambassador Richard Holbrooke, the chief U.S. negotiator at Dayton, recalled, "I told [President Franjo] Tudjman [of Croatia] [that] the [ground] offensive had great value to the negotiations. It would be much easier to retain at the table what had been won on the battlefield than to get the Serbs to give up territory they had controlled for several years."

BACK TO THE BALKANS

The 1999 war in Kosovo is a more ambiguous illustration of the effectiveness of combined-power attacks, because it still is not entirely clear what pushed Milosevic to surrender Kosovo to NATO forces on June 3, 1999. Of the three most plausible theories for the war's end, however, the most convincing is that it was NATO's threat to invade Kosovo by using air power and ground forces simultaneously that turned the tide.

The first -- and least likely -- explanation for Milosevic's surrender is that he believed that the Kosovo Liberation Army (KLA) might seize Kosovo with the support of NATO tactical air power. Although the KLA did grow stronger during the war and NATO air power destroyed some Serbian heavy equipment during its 78-day campaign in the spring, the KLA remained far too weak to seriously threaten the Serbian army. It had not recorded a single offensive success -- not even by the war's end -- and it would have been no match for the Serbian army, which still had 47,000 soldiers and more than 800 tanks, armored personnel carriers, and pieces of heavy artillery -- all in good condition -- when it pulled out.

Another theory holds that Milosevic surrendered under the threat that NATO might use strategic air power against Serb civilians. Although this explanation cannot be ruled out categorically without serious evidence of Milosevic's motivations, it too seems unconvincing. In the 90-year history of offensive air power, threats to inflict harm on civilian populations by conventional bombing have never forced an adversary to abandon important goals.

There is little reason to think that Kosovo would be the first exception to this rule. NATO bombs killed about 500 Serb civilians -- a modest toll by historical standards. Strategic air power had damaged Serbian infrastructure, including oil-refining capability, major bridges, and, temporarily, the electric-power grid. But by the time Milosevic surrendered, the rate of attacks against new strategic targets was sharply declining, especially in the weeks after NATO had embarrassed itself by bombing the Chinese embassy in Belgrade. Moreover, it is unlikely that NATO would have deliberately chosen to inflict much more harm on civilians, given that public opinion in the West would not permit the direct targeting of residential areas or food stocks.

Even if NATO had set out to do so, there is good evidence that severe economic losses to the Serbian people would have had little influence on Milosevic's behavior. Serbian society had already absorbed significant economic pain. Sanctions had cut Serbia's GNP by half between 1989 and 1998. And for five years before the bombing, more than 25 percent of Serbia's population had been chronically unemployed. Nor was there any sign that Serbia was on the verge of a civilian uprising. By all accounts, the Serbs were becoming apathetic as the bombing continued. If anything, it was Milosevic's surrender that prompted street protests in the summer of 1999, and many of the demonstrators wanted him replaced because he had lost Kosovo, not because the Serbian economy had been damaged.

The more likely explanation, then, is that Milosevic surrendered from fear that NATO would invade Kosovo, with the devastating help of precision air power. In early June 1999, the United States, the United Kingdom, and other NATO countries were about to formalize a decision to mount a ground invasion of Kosovo. Former Russian Prime Minister Viktor Chernomyrdin undoubtedly communicated to Milosevic, with whom he met numerous times that spring, that a ground war was coming. (On June 8, Chernomyrdin said in a press conference in Moscow, "If the current peace plan for a settlement in Kosovo is not carried out, the situation in the region may develop according to a different scenario. NATO has a plan for carrying out a ground operation.") The United States and the United Kingdom also took strong measures to make that threat credible. Coalition forces widened supply roads in Albania and deployed more than 35,000 troops on Kosovo's borders, while the United Kingdom called up 30,000 ground-force reservists.

Anticipating a ground attack by NATO, Russia and Serbia tried to establish a Russian military presence in northeastern Kosovo in order to partition the region and retain control over some of it. Although the effort failed, it suggests that the Serbs and the Russians considered the threat of a NATO invasion credible and believed that Serbia would be defeated.

TOPPLING THE TALIBAN

The United States won the 2001 war in Afghanistan by imitating and updating the blueprint it had tested in Bosnia, combining precision air power with ground attacks by local troops. Once again the tactic proved devastating. The Taliban's front lines collapsed within days of first being battered from the air and on the ground, opening the way for the Northern Alliance to quickly overrun Mazar-i-Sharif and Kabul.

Since the Taliban had virtually no air power and meager air defenses, U.S. air supremacy was assured before the first bomb fell. The first month of bombing, October 2001, thus focused on command-and-control facilities and other leadership targets. But after that strategy failed to kill Mullah Omar or other critical enemy leaders, air power was turned against the Taliban's 25,000 or so troops in northern Afghanistan, most of which were concentrated in the front lines. In early November, U.S. special operations forces teamed up with U.S. Air Force combat controllers to use U.S. air power to support Northern Alliance assaults on the ground. At that point, the Northern Alliance, with its few tanks and 20,000 troops, controlled just ten percent of the country and was losing against the Taliban.

The hammer-and-anvil strategy most clearly showed its worth at Bai Beche, on November 5, during a key opening battle in the fight for Mazar-i-Sharif. Northern Alliance troops charged the enemy's front lines at Bai Beche, while dust and smoke from a recent bombing raid still hung in the air. Remaining Taliban fighters simply abandoned their positions to avoid capture or death. Within a week, Mazar-i-Sharif fell, prompting many warlords across the country to defect to the Northern Alliance. This in turn allowed the insertion of yet more U.S. special operations teams and U.S. Air Force combat controllers. Kabul fell a few days later, with hardly a fight, as did Kandahar, the last major Taliban outpost, on December 9.

As the war in Afghanistan shows, the hammer-and-anvil strategy is no more effective than the decapitation strategy at killing enemy leaders or combating lightly armed and loosely organized insurgencies. But it is far more successful at achieving the objective that wins major military victories today: defeating an enemy's capacity to organize its resistance by concentrating large ground forces.

UNSHOCKED, UNAWED

In the Iraq war last year, the United States quickly conquered Baghdad and vast portions of Iraq with few casualties. Although full information about the tactics the United States used there is still unavailable, it appears that the war was won once U.S. air power shifted from attacking leadership targets to bombing Iraq's Republican Guard and other regular military units. The air raids enabled U.S. ground forces to move relentlessly through many contested chokepoints and overrun key strategic positions before major Iraqi combat units could reorganize for a protracted defense of Baghdad.

The war began with an effort to shock and awe the Iraqi leadership into capitulating without a fight, but this quickly failed. As a result, U.S. air power was soon turned against Iraq's forces in the field. Saddam had deployed them along the key approaches to Baghdad, rather than at the country's borders, probably in an effort to inflict significant casualties on U.S. ground forces, or slow them down, on their way to the capital. Tens of thousands of troops -- 40,000 according to Baghdad, 24,000 according to coalition intelligence -- from Saddam's most loyal forces, Republican Guard divisions, and other stalwart regular divisions, formed a defensive ring south of Baghdad. For ten days, the Republican Guard and other key divisions withstood intense U.S. bombardment. More than half of the 28,000 bombs dropped by U.S. pilots during the war were directed against the Republican Guard, and more than two-thirds of those were precision strikes aimed at heavy armor and other vehicles. Relatively few Iraqi troops seem to have been killed, but strikes on their heavy armor apparently compelled most of them to keep away from the equipment, effectively disabling Iraqi resistance to the approaching U.S. ground forces. According to the Pentagon, all but 19 of the Republican Guard's 850 tanks had been destroyed or abandoned, and only 40 of its 550 artillery pieces were still usable.

Yet the breaking point in the war appears to have come during the second week, when U.S. ground forces advanced against Iraqi positions that had been and were still being pounded from the air. Caught in a vise between air strikes and ground attacks, most Iraqi troops deserted. As Brigadier General Allen Peck, a key member of the air command center, put it, "Ground troops forced the enemy's hand. If they massed, air power could kill them. If they scattered they would get cut through by the ground forces." Washington's victory in the Iraq war marked another success for the combined-power strategy.

IT AIN'T BROKE

Over a decade into the precision revolution, the record points to a simple conclusion: the greater accuracy and surveillance capabilities of today's precision equipment enable air power to support ground campaigns far more effectively than in the past. Under some circumstances, air power has even become the military's main force, with ground power operating in a supporting role. Precision weaponry has not, however, eliminated the need for significant ground forces. There has been a precision revolution, but not the one touted by air power's advocates. The real revolution has not turned leadership targeting into a winning strategy; it has multiplied the combined effectiveness of air and ground power against enemy forces on the battlefield.

This analysis has important implications for the future of the U.S. military. Advocates of the decapitation strategy are calling for a fundamental transformation of the U.S. armed forces. They argue that the United States should rely more heavily on strategic air power and long-range standoff strikes by naval forces. At the same time, they argue for decreasing the role of the U.S. Army and converting its heavy combat divisions into light formations that would swarm around the enemy, rather than confront it head-on. Such a transformation would make sense if the United States could effectively destroy enemy leaders or their ability to command their forces. But decapitation alone is an unreliable strategy, and the U.S. military should not be reformed according to it -- or in any way that undercuts proven tactics, especially when they are more potent than ever.

Integration, not transformation, is the way to make the U.S. military more effective in the future. The precision revolution has already transformed the nature of U.S. military power. The recent proliferation of cheap computers -- which brought microelectronics to weaponry -- has facilitated most tasks in nearly all areas of air, ground, and naval warfare. These tasks rely heavily on advanced sensors, precision-guided munitions, and computerized information processing. U.S. military forces are now more effectively destructive, at greater range and speed, than ever before. Although diffusion of precision technology throughout the U.S. military will surely continue, it has already transformed the way each of the military's branches operates.

What the U.S. military must do next is integrate the reconnaissance, maneuver, and tactical-targeting systems that currently operate separately in its individual services. The increasing lethality of high-accuracy weapons makes the combination of firepower and movement much more powerful when air and surface forces work together. If the first two decades of the precision revolution were about bringing microelectronics to weaponry, the next should be about integrating the separate systems in the military's various branches that run on this sophisticated equipment.

The main contribution that the U.S. Air Force can make would be to increase its capacity to carry large numbers of bombs to operational theaters, rather than its ability to deliver fewer munitions through stealthy means of penetration. For decades to come, there will be a greater need for relatively cheap tactical strike aircraft, such as fast-disappearing aircraft from the Cold War (A-10s, F-111s, and B-52s), than for billion-dollar strategic bombers that can fly 10,000 miles at a time but can conduct only a handful of sorties every few days. A few F-22s (or electronically upgraded F-15s) are necessary to secure the superiority of the U.S. Air Force, but what the force needs above all is a new generation of "bomb trucks."

The leading advocates of the precision revolution have it exactly backwards. Precision weaponry has done little to enhance the coercive strength of enemy decapitation or other new strategies, which often fail because of inadequate intelligence. After a decade and a half of trying -- and failing -- to solve this intelligence problem, it may be time to recognize that it will not be overcome any time soon. Until it is, the combined use of air power and ground forces -- whose potency has been multiplied by precision weapons -- remains the most effective way for the United States to win major wars.

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Citation: Robert A. Pape. "The True Worth of Air Power," Foreign Affairs, March/April 2004.
Original URL: http://www.ciaonet.org/olj/fa/fa_marapr04/par01.html
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