IN A lively, ongoing debate, some authors have credited General Petraeus with transforming the United States military and wonder if his success will have long-term impacts. The most visible part of the debate over this legacy concerns whether the future of the United States Army lies in counterinsurgency (COIN) operations or a return to conventional combat. Initially an internal debate, it has become wide-ranging and moved from internal Department of Defense (DOD) journals like Military Review to industry publications like Armed Forces Journal to general press such as the Atlantic.

The fiery back-and-forth has focused on answering three pressing questions: whether or not a "surge" will work in Afghanistan; what types of wars we will fight in the future; and how the United States government should invest and train for what is to come. But the entire discussion rests on a false premise. The debate has identified the General's legacy as that of counterinsurgency strategy or, even further from the mark, as the success of the surge. But in fact, what the General has succeeded in doing is far more complex, far more important and potentially far more universally applicable than the simplistic notion of debating the value of preparation for counterinsurgency or conventional warfare-or worse, a simple "surge."

Petraeus's real legacy is that of a general who understood and then adapted to fight the war he was in. It seems obvious, and is even one of Clausewitz's most widely quoted passages, but the fact remains our system has not been particularly good at that "first, most far-reaching act of judgment . . . to establish . . . the kind of war on which they are embarking. . . . "

As Linda Robinson carefully documented in Tell Me How This Ends, General Petraeus did not set out to completely change and restructure the United States Army, much less the entire armed forces. Rather, he did what was needed to put one of the wars we are in on the path to success. Petraeus started by carefully analyzing the situation on the ground, which forced the administration to see that the conflict was morphing into a civil war between Sunni and Shia. Thus, if there is a Petraeus "doctrine," it appears to be based on the concept of planning your campaign based on facts on the ground. While apparently simple, doing this requires serious intellectual effort both on the part of the individual and the institution, and the flexibility of both to adapt as understanding grows. But the greatest challenge is for the commander to rise to a level of exceptional judgment and will in order to guide the campaign based on that understanding.

Thus Petraeus's campaign in Iraq (and hopefully his tenure as CENTCOM commander) will provide fodder for staff studies for generations of new officers and NCOs. However, whether or not it endures is not so much a measure of the man as it is of the military system.

Believing a simple "surge" of a few brigades essentially solved the conflict in Iraq shows both a misunderstanding of how Iraq changed and a woeful underestimation of the difficultly of achieving its remarkable results. Thinking that a similar outcome will be easily accomplished in Afghanistan incorrectly views the Petraeus legacy as a cookie-cutter approach to counterinsurgency.

As General Petraeus demonstrated in Iraq, one must first understand that there is no universal approach to counterinsurgency. All wars flow from the economic, political and social conditions of the adversaries. Due to its character as an essentially political struggle for power, COIN is even more dependent on these conditions than conventional war. Thus, what works against one insurgency will not necessarily work against another. Further, like all complex situations, COIN does not respond to a single input-such as the surge of thirty thousand troops to Iraq. It is more than just throwing troops at the problem. Such wars respond only to a careful analysis followed by an integrated strategy grounded in an understanding of the unique characteristics of that particular fight.

Based on such an analysis, the surge in Iraq brought together a number of mutually reinforcing factors on top of the addition of five combat brigades: a major political effort to reconcile the Shia, Sunni and Kurdish factions; a shift of emphasis from hunting terrorists to protecting the Iraqi population; a shift in operational approach from operating from large hard bases to living among the people; the application of a new doctrine based on an understanding of the insurgency across U.S. forces in Iraq; a shift in the political stance of many Sunni tribal leaders from fighting the Americans to assisting us in providing security for their neighborhoods; and Moktada al-Sadr's declaration of a truce. None of these factors individually would have led to a decrease in hostilities; even this comprehensive approach has not resolved the situation. The willingness to share power among factions remains tenuous and will require patient, long-term confidence building-backed by U.S. troops.

BECAUSE OF Petraeus's success, murmurs of a COIN takeover of the military sent the strategists sharpening their swords. It has become a battle between the COIN supporters and the COIN naysayers. One side sees the future of conflict as being dominated by irregular war. The wars we are fighting today represent the wars we will fight for the next decade or longer. They will not be wars of choice like Iraq but wars of necessity like Afghanistan. As articulated by retired-army officer John Nagl, threats will arise in undergoverned spaces and it will be essential that the United States assists those governments in building functioning societies. Thus our forces must focus on preparing to fight these irregular wars, putting an emphasis on early intervention with advisers and building capacity across the host-nation government. This argument draws strength from the fact that we are currently deeply involved in two such wars and continue a global effort against terrorists. Only after four years of conflict did our ground forces adjust to dealing with these threats. In addition, the current absence of a near-peer competitor makes such wars seem the most likely to engage the United States in the next decade or two.

Those on the other side of the argument fear that today's conflicts are an aberration. They worry not only that our future enemies will be major powers rather than guerilla fighters, but also that the concept of a COIN-dominated force has already swept the military establishment and seriously damaged our ability to conduct conventional operations. They fear this will result in our being unable to fight the near-peer competitor they feel represents the real threat to the United States.

A leading voice arguing on this side of the aisle is Colonel Gian Gentile. An Iraq War veteran, Gentile has made the case in magazine articles and blogs, and in personal appearances, that the army has shifted focus almost exclusively to COIN and thus will not be ready to fight a conventional war. In particular, he interprets the Israeli failure in the Israel-Hezbollah war as a demonstration of what happens to an army that focuses too heavily on COIN. He also points to the Russian incursion into Georgia as an example of the dominant role of conventional combat. He bolsters his argument by citing a paper written by three artillery colonels expressing concern that army artillery, forced to take on nontraditional roles in Iraq, is losing the ability to perform its core tasks.

Gentile and his supporters feel the real mission of the armed forces is to be prepared to fight major conventional enemies. This mission requires specific, difficult-to-maintain skills and therefore is the rightful focus of the armed forces. Military leadership should resist commitment to the kind of long-term nation-building efforts we see in Iraq and Afghanistan. Such a future rejects a focus on irregular war and provides justification for our current spending as well as robust research-and-development programs to ensure we can stay technologically ahead of such a near-peer competitor.

With the demise of the Soviet Union, and China at least ten years away from being able to project power outside its immediate area (as the Pentagon acknowledges), this idea has had a difficult time gaining traction. Its proponents point to China's modernization and Russia's recent aggressiveness to justify major investments. However, as the actual events in Georgia have clarified, Russia is much less threatening than is portrayed. While still possessing the second-most-powerful nuclear arsenal in the world, Russia required months of preparation and training to be ready to project a relatively small force barely fifty miles across its own borders. Given that Russia's borders are now more than five hundred miles further east than the Soviet Union's were, and that the country is suffering a population decline of one million people per year, it is difficult to imagine Russia as a major conventional threat.

That leaves China. According to the near-peer-competitor scenario, the United States must invest heavily in air and naval forces to fight the dragon. In particular, we must defeat China's so-called anti-access program, which is designed to prevent U.S. forces from moving into an ever-increasing "denied area" in the western Pacific. This scenario sees the United States taking the fight close to China rather than adopting a distant strangulation strategy that cuts off Beijing's essential trade routes. However, proponents who seek increased naval and aviation funding based on this scenario assume that we will not attempt to project land forces into China and thus do not need a massive increase in spending in this area. Interestingly, the proponents of this strategic-investment plan have also not discussed what would trigger a conflict with China or how two nuclear-armed powers can fight a war that threatens vital interests of both.

Recently, a third view has emerged that suggests we will not face either of these extremes but instead will encounter a complex mixture of warfare. Its proponents build on the 2006 Quadrennial Defense Review that lists four types of challenges we can expect to face: traditional, irregular, disruptive and catastrophic.¹ They argue that future wars will actually be a combination of these threats-hybrid wars. From this point of view, the Israel-Hezbollah war is not a demonstration of the continued relevance of conventional conflict, as the Gentiles of the world would have it, but rather it is the poster child of hybrid war: Hezbollah used a combination of local guerrilla fighters, advanced technology (missiles, communications intercepts, UAVs) and a sophisticated strategic-communication campaign to fight the Israelis to a standstill. Some see this as a new form of war-fighting. Yet, we saw this same mix of regular and guerrilla forces equipped with high- and low-technology weapons in the American Revolution, the Napoleonic Wars (particularly in Spain and Russia), the Communist Revolution in China and the Indochina wars. In each of these campaigns, the conventionally more powerful force found itself having to fight a mix of conventional and guerrilla forces. Hybrid war is not new, but our growing recognition of its attendant complexities is-and we are better for it.

The key point of contention obviously remains whether the services should reorganize under the assumption that conventional or irregular warfare will dominate the future.

THE NATURE of bureaucracies, though, means that the question is never how they should respond, but rather of how they will respond. So, the camp of conventional warriors has little to fear. No matter what the legacy of Petraeus, it is almost impossible that counterinsurgency operations will drive the organization and equipping of the military for three reasons.

First, conventional warfare remains the dominant culture of the Department of Defense. Despite seven years of irregular war and Secretary Gates urging us to focus on the wars we are in, most of the department remains focused on conventional war.

Second, the armed forces' own bureaucracy would make it extremely difficult to change. Our current recruiting, training, education, career development and force structure were designed to fight a conventional enemy. Like all bureaucracies, they do what they are designed to do-and require great effort to shift from their original purpose. The Iraq and Afghanistan wars have provided sufficient momentum to move the bureaucracies to focus on counterinsurgency. However, the effort will have to be sustained for at least a generation for it to become permanent. Otherwise, the organizations, processes and procedures will inevitably push our forces back toward the institutions' conventional comfort zone.

It is truly remarkable the number of leading voices in the debate that belong to those officers who have advanced degrees in the humanities. Their education seems to provide a wider aperture to look at the world. Yet, during the 1990s and even through most of the current conflicts, the services have not treated advanced civilian education as career enhancing. Further, our system often punishes those who stray from an approved career path. Unfortunately, this produces an echo-chamber effect where most of each service's leaders have the same career paths and, as a result, the same education and life experience. Only after seven years of war did the last promotion boards finally select colonels who had served as advisers for general-officer rank. Despite the fact that the administration has been stating that training Iraqi security forces is our most important mission since at least 2004, the services had failed to promote a single adviser to general officer. The promotion record indicates the army and Marine Corps still value commanding U.S. units above the much more challenging problem of advising and building Iraqi and Afghan forces. Only if we can change these career and education paths can we sustain the changes of the last few years.

Finally, the conventional path of the military is all the more intractable because of Congress's interest in maintaining the status quo. The question of where the Pentagon will spend its money is the underlying issue-and perhaps the most important one inside the Beltway. The defense industry has expressed concern that COIN will dominate U.S. spending and thus leave us without the big-ticket items necessary to fight a high-technology near-peer competitor. DOD, Congress and the defense industry all have enormous vested interests in building, equipping and maintaining high-end, conventional forces. While the equipment, advanced education and training required in COIN represent a relatively small cost, the additional manpower will consume large resources. The current end-strength increase of sixty-five thousand soldiers and twenty-seven thousand marines will cost $108 billion during the ramp-up to 2012 and an additional $12 billion per year after that. As always, personnel costs will be competing directly with procurement accounts for DOD dollars. Naturally, American voters will pressure their congressmen to "bring home the pork" in the form of military-hardware contracts. Thus, Congress has a vested interest in shaping the forces for conventional conflict.

One can hope that despite these factors, General Petraeus's legacy will be a United States that studies and understands the kind of war upon which we embark, rather than debating between the false choice of a COIN or conventionally dominated military.

BUT NO matter the bureaucratic and institutional inertia, we should answer the question not only of what will happen but also how we would best be served by our military. When faced with determining whether the U.S. military must exclusively focus on conventional or irregular warfare, one is not faced with an either-or proposition. Rather, we must do both. Unfortunately, despite the numerous examples each side can draw upon to reinforce its vision, the reality is we are not very good at predicting the future. And, as always, the enemy gets a vote. An intelligent enemy will strive to strike our weakest points. Thus, focusing our forces on conventional operations will drive enemies to irregular warfare, while a force focused on irregular warfare will encourage potential enemies to develop effective high-technology conventional forces.

Prudence requires we be ready to fight across the entire spectrum of potential conflict. So, a better question is how to organize, educate, train and equip a force that is capable of doing so. But trying to answer this question is complicated by the reality that even if we succeed in withdrawing our forces from Iraq and Afghanistan in the near future, it is impossible for a force to train equally across the full range of potential conflicts. We will have to make choices.

We need a flexible force that can organize to fight nation-states as well as nonstate actors. Rather than optimizing our ground forces to fight conventional opponents, we need to establish a joint force capable of fighting well-trained units equipped with highly capable weapons systems, as well as very lightly armed irregulars who learn on the job. In short, we need a medium-weight joint force capable of operating across the spectrum of war rather than one optimized for fighting high-intensity warfare against nation-states or one primarily prepared for irregular conflicts.

Elements of the force (fighters, bombers, tanks, artillery, blue-water navy) should focus on fighting conventional wars, though they should still conduct some training for irregular war. We may choose to organize a portion of our ground forces specifically for conventional operations. A single army corps can maintain the corporate knowledge necessary for such operations and provide a base for rapid mobilization in the face of a conventional threat.

Other parts of the force should focus on irregular war: advisory groups, military police, civil affairs, human intelligence teams and other key elements for this type of conflict. We have to develop sufficient numbers of military and nonmilitary advisers to assist other nations against insurgency. Since military advisers must be relatively senior personnel, we may have to expand the number of field-grade officers and senior noncommissioned officers available for such assignments. We can do so by sharply reducing senior-level staffs. Rather than grinding away on these staffs, the personnel would spend their time either becoming expert on their region or teaching others about the area. These people should be the repository of the most challenging cultural and developmental knowledge and skills. And, certainly in the immediate future, they can be effectively employed in a wide range of countries.

The bulk of the force-infantry, rotary-wing aviation, light-attack aviation, inshore naval forces and logistics-should train to fight across the spectrum. Of course, in the near term, this remains mostly an academic discussion for the army and Marine Corps. Because current operational demands are so intense, these forces must focus on the COIN training essential for their immediate deployments. Implementation of across-the-spectrum training must wait until we withdraw sufficient troops to restore a normal rotation cycle.

Some critics will be skeptical that this type of training is possible; to some extent this is valid. It is impossible to train equally well for all contingencies. So, our forces should lean toward preparing to fight irregular enemies simply because it is harder to train forces for irregular war than for conventional war. COIN is rightfully referred to as the graduate level of war. For those forces that have the institutional ability to learn, it takes about three to four years for a conventionally oriented force to become effective against an insurgency. This is reflected by the British experience in Malaya, and the United States in Vietnam and Iraq. Unfortunately, conventional forces very often fail to adapt-the French in Indochina and Algeria, the Soviets in Afghanistan and Chechnya, and the Belgians, Dutch and Portuguese in their colonies.

By contrast, forces adapt fairly rapidly to conventional war. In the two years between December 1941 and December 1943, U.S. Army ground and air forces increased from about 1.5 million to 7.5 million. Further, despite dire predictions about confrontations with future near-peer competitors, other states' conventional forces cannot be an existential threat as long as we have a viable nuclear deterrent to fall back on.

And any attempt by an enemy to create a capable conventional force will require industrial investment as well as highly visible training efforts. If a potential enemy should seek to create a powerful conventional force, we will have significant warning and can adjust our training accordingly. In contrast, an enemy who chooses to fight us in an unconventional manner can prepare with little visible effort. Thus our strategic preparations should be biased toward irregular war.

The future remains uncertain. But as Colin Gray predicted, we are well on our way to "another bloody century." We cannot predict the future, but we should prepare to operate with a bias toward the kinds of wars we are fighting today by carefully maintaining the full range of skills we need to fight across the spectrum of conflict.

A SERIES of well-documented, egregious mistakes by the administration from 2003-2006 left General Petraeus facing an unprecedented level of Iraqi inter-sectarian violence when he took command in 2006. With a thoughtful analysis of the situation and a well-developed, integrated political-military plan, Petraeus, along with Ambassador Ryan Crocker, changed the course of the war. Yet, as Petraeus noted in his change-of-command address, Iraq will continue to require careful attention and a long-term commitment from the United States.

With his promotion to commander of Central Command, General Petraeus is establishing a serious brain trust to conduct a similar analysis of the conflict in Afghanistan and Pakistan. The challenge here is at least as great as Iraq. Increasing the difficulty is the fact that we have lacked a coherent approach since Ambassador Zalmay Khalilzad and Lieutenant General David Barno left in 2005. Since then, we have turned responsibility for Afghanistan over to NATO-vastly increasing the political, economic and military negotiation and coordination required to develop a coherent international approach. Only when we understand the regional factors that are driving this conflict can the United States-in conjunction with our allies-devise an adequate strategy to ensure the stability of Pakistan and the development of a peaceful Afghanistan. Petraeus, as regional combatant commander, should bring the broader perspective required to this analysis. It is essential that the new administration look past simple solutions to determine the depth and breadth of the commitment needed. If the Petraeus legacy has shown us anything, it is that simple solutions do not exist.

T. X. Hammes retired from the Marine Corps in 2005 after thirty years of service, mostly in the operational forces. He works on national-security issues.

¹Traditional refers to conventional war; irregular to insurgencies and terrorism; disruptive to the use of new technology or techniques that "disrupt" or negate our traditional strengths in conventional war; and catastrophic to attacks with WMD.