On 12 August 2010, the U.S. Secretary of Defense, Robert M. Gates, delivered a speech at the Marine Memorial Club in San Francisco in which he challenged Marines to “define the unique mission of the Marine Corps going forward . . . .”! The Secretary made the point that the wars in Iraq and Afghanistan have turned the Marine Corps into a “second land army.” This metamorphosis occurred for good reasons, but the time has come to consider the Marine Corps‘ future beyond these conflicts, and in a constrained fiscal climate. The Marine Corps must also be relevant to the types of threats the Nation is likely to face in the future. Given these requirements and constraints, the Secretary has challenged the Marine Corps to rethink its role in national defense. In every challenge there is an opportunity. This is the case for the Marine Corps today. Secretary Gates’ challenge opens the door for the Marine Corps to become the Nation’s primary force for fighting fourth-generation wars (4GWs).

The Marine Corps can no longer be confident that its capability to conduct amphibious forcible entry guarantees its existence. The Marine Corps will remain responsible for maintaining a forcible entry capability in the future, but in his comments the Secretary raised the question of how much amphibious capability the Nation requires. His concern is that “anti-ship missiles with long range and high accuracy may make it necessary to debark from ships 25 or 40 or 60 or more miles at sea,” which might make an amphibious assault prohibitive in terms of cost and potential risks. In addition, large-scale amphibious assaults are only likely against a state opponent. Nonstate actors of the sort Marines are now fighting have no borders or beaches to defend. Against such enemies, amphibious landings may simply be a way for the Marine Corps to get to the fight.

The Army should have primary responsibility for fighting any state that goes to war with the United States, with the Marine Corps playing a supporting role. The U.S. Army was designed for just such a conflict; it makes little sense for the Army to redefine its role. Instead, the Marine Corps, as a smaller, more agile force, should change its role to fill the capability gap that remains. That gap is fighting 4GWs, wars against opponents who are not states.

4GWs are the most likely conflicts in the future. In an article in the Marine Corps Gazette in 1989, “The Changing Face of War,” a group led by William S. Lind laid out a framework for thinking about war.2 4GW is the result of the state’s loss of its monopoly on war. The concept of state as the sole entity legally permitted to use violence dates from the time of the Treaty of Westphalia that ended Europe’s Thirty Year’s War in 1648. Before that time, many other entities conducted wars – business enterprises, families, tribes, religions, etc. After 350 years, the idea that many institutions or groups other than the state may conduct wars is difficult to conceive. The confusion is reflected in the terms used to describe 4GWs, such as “terrorism” or “crime,” when they are, in fact, wars.

The state arose primarily to provide security. In todays world it often fails to deliver on this promise. As a result, citizens of failing states have begun to transfer their primary loyalty away from the state that can no longer provide the security it promised, and they have bestowed this loyalty on some other entity, such as their religion, tribe, gang, or ideology. These other entities provide security and identity that was once provided by the state.

Consider the example of al-Qaeda (AQ). AQ is not a nation-state, nor does it control one. It is a transnational organization that has attempted to hijack Islam in an effort to draw recruits and claim legitimacy. As an organization without a states resources, AQ draws support from those people who feel alienated from their states. It has recruited supporters from states all over the globe. ACl conducted attacks on U.S. Embassies in Africa in the late 1990s and against the USS Cole (DDG 67) in 2000. These were clearly acts of war, but the United States treated them simply as acts of terrorism. It was not until the attacks of 1 1 September 2001 that the United States was forced to recognize the threat posed by AQ. As more states fail or have difficulty meeting the needs of their populations, 4GWs will spread. The conflicts in Iraq and Afghanistan are both examples of 4GWs.

Fourth-generation opponents will attempt to avoid the strengths of the U.S. military, especially its massive fire-power. This should come as no surprise. No sane enemy will fight in a manner that plays to its opponents strengths. The entire world knows that the U.S. military is technologically advanced (perhaps “dependent” is a better word) and can kill any target it can identify. Future 4GW adversaries will be unable to match U.S. technology and will not attempt to do so. They will attempt to draw U.S. forces into conflicts that not only minimize our advantages but also turn our strengths into disadvantages.

Many future conflicts will be fought in urban or other populated terrain as 4GW enemies attempt to make it difficult for U.S. forces to target them. In his book, The Utility of Force, British Gen Rupert Smith wrote that the conflicts of the future would be “war amongst the people.”3 Given the difficulty that U.S. forces have had in Iraq and Afghanistan in rooting out the insurgents from among the civilian population, it is likely other opponents will present us with the same problem in the future. America needs a force that specializes m “war amongst the people,” which is very different from state versus state conflict like Operation DESERT STORM.

For the Marine Corps, becoming the U.S. military’s primary force for dealing with 4GWs has several advantages. The Marine Corps and Army would have roles that would be complementary and clearly defined. The Marine Corps could get out of the business of acting as a second land army for fighting DESERT STORM-style conflicts. Marines would maintain their relevance; the types of wars most likely to occur in the future are 4GWs. The Marine Corps would be able to capitalize on some of its traditional strengths. In many respects, the Marine Corps would simply be getting back to its roots.

The Marine Corps has a long and storied history of involvement with counterinsurgency and brushfire wars. The majority of the conflicts in which Marines have found themselves have been “small wars.” In fact, the Marine Corps quite literally wrote the book on how to fight a small war.4 The Marine Corps‘ focus on conducting amphibious forcible entry is relatively new. Throughout most of the Service’s history, Marines have spent most of their time conducting missions other than amphibious forcible entry. The Marine Corps must certainly maintain an amphibious capability for the Nation, but it should no longer be the only mission that uniquely defines the Marine Corps.

For 4GWs, the Marine Corps has many essential qualities including, importantly, the high quality of its recruits and the self-discipline of its Marines. Fighting 4GWs is much more demanding than fighting conventional state-on-state wars. It requires individuals who can shift instantly from aggressiveness to self-restraint. In 4GWs, among the civilian populace, the heavy use of firepower is a recipe for defeat. Many situations will call for use of small arms only as Marines make every effort to deescalate. This is counterintuitive to someone trained that his own personal safety lies in possessing and using overwhelming firepower. In fact, it may be necessary to sustain more casualties than one inflicts in order to prevail in 4GWs. Fighting in such a complex environment requires someone with the ability to think quickly on his feet, the courage to do what is right even when it is risky, and the self-discipline to refrain from killing when it is either not necessary or counterproductive to the mission. These are qualities Marines are today demonstrating in Afghanistan.

If the Marine Corps is to become the Nations force of choice for fighting 4GWs, several major changes are necessary. The first is adopting the framework of the “four generations of modern war” as doctrine. There may be a useful analogy to recent Marine Corps history. The Marine Corps adopted maneuver warfare as doctrine in 1989. (Maneuver warfare defines the third generation of modern war.) Marine officers informally did much of the intellectual work for this doctrinal change. The adoption of maneuver warfare as doctrine was a tremendous political and public relations windfall for the Marine Corps. It demonstrated to the American people that the Marine Corps is a progressive and forward-thinking organization. The adoption of the four generations of modern war framework as doctrine has the potential to repeat that success.

It is also necessary to restore the intellectual climate that prevailed in the Marine Corps during Gen Alfred M. Gray’s period as Commandant. During that time, Gen Gray encouraged Marines to read, think, talk, and write about maneuvet warfare. He revitalized the Marine Corps‘ professional military education program as part of this effort. A similar intellectual effort will be necessary for the Marine Corps to come to grips with 4GW, and an intellectually open atmosphere will be required throughout the Corps.

The Marine Corps must also develop some true light infantry. The U.S. military currently has no light infantry. What is now referred to as light infantry is, in actuality, line infantry. A cursory examination of the units that currently profess to be light infantry (including Marine units) will quickly reveal that there is nothing light about them. Part of the reason that the infantry the U.S. military has used in Iraq and Afghanistan has had such difficulty is because, contrary to their appellation, they are actually line infantry.

The greatest difference between light and line infantry has litde to do with gear. The primary difference between light and line infantry is the mindset of each. True light infantry is far more resourceful and self-reliant than line infantry. True light infantry is habituated to operating in an austere environment far from friendly bases and logistical support. In some circumstances, light infantry can live off the country. Line infantry requires a ponderous and expensive logistical tail to sustain ir. Light infantry is used to operating cut off from other friendly units. Line infantry units are extremely uncomfortable when they are isolated from other units or are far from friendly fire support. A light infantryman has an ambush mentality and is always seeking to exploit opportunities to discomfit the enemy. The mindset of a light infantryman is that of a hunter stalking his prey, not that of a football player attempting to push the opponent’s defensive line down the field.

There is no “one size fits all” force. Light infantry, line infantry, armored, mechanized, or motorized forces all have strengths and weaknesses. The weaknesses of line infantry have been cruelly exposed in Iraq and Afghanistan. Other than a few kinetic operations, the limitations of heavy armored formations have also been demonstrated; it is difficult to interact with the populace from behind several tons of armor. Light infantry would have limited usefulness during mobile warfare in open terrain (think World War II in North Africa). Such a fight would place a light infantry force at a mobility disadvantage and, most likely, at a firepower disadvantage as well. Light infantry, however, is well suited to warfare in close terrain. Light infantry is extremely valuable in 4GWs because it can move faster and farther on its feet than can most opponents.

Transitioning to a primarily light infantry force would have the added advantage of making the Marine Corps cheap again. The Marine Corps still provides the greatest “bang for the buck” of any U.S. Service, but given the unsustainable amounts of money spent on U.S. national defense (more than the rest of the world combined), this is not saying a lot. Light infantry costs less while still providing a powerful capability. Before the wars in Iraq and Afghanistan, Marines had a culture of doing more with less, of which they were quite proud. In this sense, transitioning to a fight infantry force would allow the Marine Corps to recapture a valuable element of its institutional culture and of its political appeal.

In fact, the Commandant of the Marine Corps is already concerned about the sustainability of current Marine Corps forces. He recently began a program to investigate ways in which the Marine Corps could reduce the amount of energy that it uses as well as cut the amount of waste produced. The goal of the program is to reduce the logistical requirements of units in the field so that there is less need to risk Marines‘ lives conducting frequent resupply operations. A force consisting of true light infantry will use less energy, require fewer resupply convoys, and ultimately save the taxpayers money.

Reorganizing many of the Marine Corps‘ combat units into light infantry will require rethinking and reorganizing the rest of the Marine Corps as well. For example, logisticians will have to consider how to resupply units that are spread out all over the battlefield, even though their requirements for resupply will be drastically reduced. Communicators will have to ensure that units have the radios necessary to talk over great distances, although fight infantry should be trained to operate even when they have no communications with higher headquarters. Fire support agencies will have to examine their organization and equipment to determine the best manner in which to provide on-call fires appropriate to a 4GW environment. Similarly, Marine Corps aviation will have to reconsider its role and the aircraft: it uses. It will no longer be enough to simply drop bombs based on a nine-line brief; the Marine on the ground will likely be more interested in what the pilot can see, as opposed to what he can destroy. All of these issues, and many more, will have to be addressed if the Marine Corps is to embrace the light infantry concept as a way to becoming the force of choice for fighting 4GWs.

The great American military theorist, CoI John Boyd, USAF(Ret), was widely quoted as saying that the proper way to build a force is, “People, ideas and hardware, in that order.” The Marine Corps already has a large number of high-quality people as a basis upon which to begin the transition to a 4GW mission, although there will be a need to retrain to the light infantry concept. What remains of this trinity is to flesh out the supporting concepts and, lastly, purchase any equipment that is necessary.

As was the case with maneuver warfare, Marines, working informally, have already done some of the intellectual work necessary to transition the Marine Corps to 4GW. Much of the Marine Corps‘ current doctrine is ideally suited to 4GW.5 4GW requires maneuver warfare, since firepower alienates the population. Marine Corps Doctrinal Publication 1, Warfìgbting, also calls for a decentralized philosophy of command and control; 4GWs can be fought in no other way. Doctrinal manuals on 4GW have already been written. They are ready for adoption. Students from the Expeditionary Warfare School’s Advanced Warfighting Seminar wrote them. The series includes two manuals that describe the fight infantry concept and how it differs from current line infantry.6

Some Marines may see Secretary Gates’ words as a challenge to their budget, pet program, or “rice bowl.” It is none of these things. There can be little doubt that in the last decade the Marine Corps, as a Service, has become a second land army. There were good reasons for this, and it was probably unavoidable. Now the Secretary of Defense has offered the Marine Corps an opportunity to rediscover and reclaim its soul, an opportunity to find its way forward again. Such opportunities come along only once in a generation, if that frequently. The Marine Corps must take advantage of this tremendous opportunity to do what is right for the Marine Corps and, more importandy, for the Nation.