In the 1990s, Commandant of the US Marine Corps Gen. Charles C. Krulak advanced the idea of what he called a “three-block war” to explain battlefield realities in an era of failed and failing nation-states. Not only was the Marine Corps operating in complex environments and executing a range of missions—including humanitarian aid and peacekeeping, alongside mid-intensity conflict—it was also operating in an atmosphere of pervasive media coverage. With the rise of the internet and cheap video equipment, the actions—or mis-actions—of Marines could spread quickly around the world. Krulak perceived the need to invest heavily in the human dimension of warfare. This was done to ensure that even the lowest-level Marine leaders were fully developed and prepared to operate effectively to contribute to the achievement of strategic objectives in this environment of ever-increasing scrutiny.

Many readers will be familiar with Krulak’s three-block war and his notion of the “strategic corporal.” Certainly military leaders at all levels who have been involved in America’s post-9/11 wars in Iraq and Afghanistan will have encountered these ideas. And yet, the nuances of Krulak’s thinking have largely been abandoned outside the Marine Corps, if they were ever truly appreciated.

To understand why requires the three-block war to be revisited, more than twenty years after Krulak originally explained the framework. In doing so, the tendency for “block inflation” becomes apparent, as does the rise of the “toxic” strategic corporal myth. By recognizing how Krulak’s ideas have been distorted, we can begin to chart the ways in which the strategic-corporal developmental philosophy is still relevant on the modern battlefield as a means of addressing war’s increasing complexity.

The “Three Block War,” as Gen. Krulak Imagined It

In the January 1999 edition of Marines Magazine, Krulak described “the Three Block War” utilizing a fictional story of Cpl. Hernandez, who finds himself in a failed and famished central African state, leading a squad, and providing humanitarian aid. Alongside that humanitarian aid effort, peacekeeping missions are being conducted and mid-intensity conflict is occurring in different blocks of the city he is operating in. Cpl. Hernandez’s challenge is to correctly identify which “block” (and related operation) of the city he is in and respond with the appropriate amount of force required to achieve tactical goals while supporting strategic objectives. This environment requires junior leaders, like Cpl. Hernandez, to “confidently make well-reasoned and independent decisions under extreme stress.” And in today’s super-connected world, Krulak continues, where internet connectivity and video equipment abound, junior leaders’ decisions and actions will likely be captured by the media and every action will meet with the scrutiny of the “court of public opinion.”

This gives the actions of even the most junior leaders a degree of strategic impact that no previous battlefield did. To develop strategic corporals, Krulak stressed three developmental priorities. The first is the instillment of the Marine Corps’ enduring ethos. By educating Marines in the virtues of the Corps with an emphasis on building character, they are enabled to appropriately address what Krulak describes as the “moral quandaries” common on the battlefield. The second priority is providing quality professional military education, which “sustain[s] the growth of technical and tactical proficiency and mental and physical toughness.” Finally, Krulak emphasized, the Marine Corps must provide examples of quality leadership to inspire Marines to “rise to the same great heights” as those who “who have set the highest standard of combat leadership” throughout the Marine Corps’ history.

Krulak presented an encouraging image of a strategic corporal who positively supported strategic objectives throughout his or her mission. In Krulak’s story, Cpl. Hernandez utilized his training and education, the latest equipment, his grounding in the Marine Corps ethos, and quality leadership role models to appropriately lead his squad. He represented a fully empowered noncommissioned officer, agile enough to stay ahead of an enemy in an environment that was “increasingly hostile, lethal, and chaotic.”

Krulak emphasized that the expected era of peace at the end of the Cold War never arrived; instead, what followed has been “an age characterized by global disorder, pervasive crisis, and constant threat of chaos.” It was in this chaotic global disorder, and in Krulak’s observations of Somalia, Bosnia, Albania, Kosovo, Macedonia, Haiti, Liberia, Nigeria, and Sierra Leone, that the three-block war metaphor was forged. Krulak never felt that the next war would be the “son of Desert Storm” but rather the “stepchild of Chechnya.” While he wrote his Marines Magazine article prior to America’s post-9/11 wars, the metaphor served as a useful guide in Iraq and Afghanistan, as it succinctly captures the complex multidimensional nature of modern warfare.

Block Inflation

Several attempts were made to build upon Krulak’s three-block war metaphor. Observers have noted a natural tendency for “block inflation” as new missions or domains of warfare were introduced. This attempted to make the metaphor more accurate to current battlefield conditions. However, block inflation didn’t also positively impact the strategic-corporal developmental philosophy, and as a result, attempts to update the metaphor may have severely weakened the critical developmental philosophy the metaphor contained.

In 2005, then Lt. Gen. James Mattis and Lt. Col. Frank Hoffman proposed “Four Block War” in their article, “Future Warfare: The Rise of Hybrid Wars.” The fourth block they proposed was “psychological or information operations.” While Mattis and Hoffman where correct in adding emphasis to this dimension, referring to it as a “block” isn’t wholly compatible with Krulak’s original metaphor. His three blocks symbolized different types of operations in different spaces (humanitarian assistance, peacekeeping, and mid-intensity conflict). This new task (“psychological or information operations”) could occur in a separate block, but is really something that can and often must accompany operations in every block of the original metaphor.

The most devastating adaptation of Krulak’s metaphor was the Canadian military’s attempt to apply it as strategy, which failed for several reasons. First, Chief of Defense Staff Gen. Rick Hillier made significant alterations of the three-block war metaphor. The blocks as defined by the Canadian military—high-intensity conflict, counterinsurgency, humanitarian aid—were incapable of being performed simultaneously (which perhaps explains why Krulak deliberately chose “mid-intensity” conflict for his vignette). For example, it would be impossible to engage in city reconstruction with active high-intensity conflict also occurring within the city. When Canadian forces applied this theory in Afghanistan’s Kandahar province in 2006-2007, they suffered a fatality rate among their soldiers that was twice that of either US or UK forces in the country. Moreover, while this metaphor, describing an urban combat environment, seemed easy to adapt for use as strategy for Canadian ground forces, there was no clear direction on how it should integrate with naval or air forces. Finally, the cost of using soldiers to perform humanitarian missions was significantly larger than that of civilian-led efforts and the presence of military forces integrated with aid workers threatened the perception of “neutrality” that humanitarian assistance seeks to foster. As it’s nearly impossible to apply Krulak’s metaphor at the operational and strategic level, the Canadian abandonment of the metaphor as a strategy “is not to be mourned.”

Toxic Strategic Corporal

Krulak’s metaphor, in certain ways, became corrupted and, as Col. Thomas Feltey has written, “forever associated with negative consequences.” Instead of acting as a catalyst for the investment in the development of junior leaders and empowering them with authority to take appropriate tactical actions, strategic leaders became overly concerned with the strategic impacts of tactical operations. This fear of strategic “mission failure” due to the actions of junior leaders caused vast degradation in the practice of mission command and eroded critical trust between leaders at various levels.

Feltey explored the history of the notion of the strategic corporal to find “its trajectory from its positive intent to its doppelganger, doomsayer variant.” He noted that the first appearance of language resembling a strategic corporal was found in the 1995 Joint Publication 3-07, Military Operations other than War. This publication underscored the need to understand political objectives “at every level from strategic to tactical,” warning of the negative consequences caused by incorrect actions of junior leaders. As Feltey reports, “this marked the first time doctrine linked policy directly to the actions of junior leaders conducting tactical engagements.” In the 2004 British Joint Warfare Publication 3-50, the strategic corporal had evolved, as Feltey described, from a positive actor to a “corporal who uncomprehendingly straddles the tactical, operational, and strategic levels of war.” The strategic corporal was seen as both an opportunity and a liability with the publishing of the 2006 US Army and Marine Corps counterinsurgency manual, but the balance would soon shift overwhelmingly to the latter. As Feltey tragically reported, “The strategic corporal moved from a 1997 idea to support an emphasis in developing leaders adaptable to new environments to . . . the 2010 version of the deleterious strategic corporal with the emphasis on commanders requiring a close overwatch of subordinates who can influence strategic outcomes directly through tactical actions.”

To test the theory of the negative impacts of a “toxic” strategic corporal, Feltey examined four of the most negative events in recent wars: the My Lai massacre, Abu Ghraib prison torture, the Blackhearts rape and murder case, and the Panjwai massacre. Two of these events took place in Iraq, and indeed Operation Iraqi Freedom should have been the proving ground for the dangerous toxic strategic corporal if these risks were significant. The availability of cheap video recording systems and internet access allowed for rapid worldwide transmission of battlefield footage. The Iraqi insurgency used significant amounts of recordings of successful attacks against coalition forces for propaganda purposes. Yet with the expansion of video evidence on the battlefield, there were remarkably few incidents with strategic impacts.

The one incident of the four Feltey examined that had a significant strategic impact, which likely poisoned the concept of the strategic corporal, was the Abu Ghraib prisoner abuses. Feltey reports, “If any battlefield event of the early 21st century had strategic influence it was Abu Ghraib—and the strategic corporal was seemed [sic] to bear the whole of responsibility.” The abuses were not just violations of the Law of Land Warfare but were offensive to the Islamic faith. The result of this single incident of “misconstrued understanding of command guidance” was significant—so significant in the minds of combat commanders that their attitudes toward junior leaders and their perceptions of the strategic corporal changed. It is important to note that Abu Ghraib was caused by members of an Army unit without the advanced development recommended by Krulak. In this regard, Abu Ghraib serves as a warning of what can occur when junior leaders aren’t developed into the strategic corporals Krulak intended.

Feltey concludes by asserting that “senior commanders and doctrinal manuals must replace the idea of the strategic corporal with the idea of junior leaders operating within an empowering environment of trust.” This relabeling of Krulak’s concept is aimed at removing negative connotations inserted by others. Instead of repackaging the concept into a new term, it would be far better to return to the positive notions of the strategic corporal by re-educating leaders about Krulak’s original concept.

The fixation on only the most negative manifestation of the strategic corporal is, as Feltey pointed out, a major risk to successful mission command. Trust is required in order to “empower agile and adaptive leaders,” which Army doctrine identifies as an essential element of mission command. Strategic leaders fearful of potential negative strategic impacts of tactical decisions made by junior leaders are unlikely to invest the full measure of trust required to maximize the advantages of mission command. Fearful of the toxic strategic corporal, strategic leaders have limited operations causing various levels of commanders to only add to these restrictions in an ongoing cascade of fear This is simply not an effective way to fight a war against a highly adaptive enemy.

Strategic-Corporal Developmental Philosophy

While the idea that forces would be able to conduct too wide an array of missions within a very limited geographic space in a dense city is a weakness of the three-block war as a concept, the need for highly developed junior leaders on the modern battlefield is beyond question. Krulak’s solutions to the problem of complex operational environments and pervasive media coverage was firmly rooted in the human dimension of warfare. All three of Krulak’s proposed lines of effort to empower the strategic corporal were aimed at the development of the individual Marine. By improving each Marine with education, training, and quality leadership examples, the Marine Corps would be better prepared to deal with twenty-first-century complex operational environments.

The focus on the human dimension is connected directly with Krulak’s personal experiences as a junior officer. Krulak commissioned in 1964 and served two tours as a company-grade officer in Vietnam. He would have witnessed in the mid-1960s both widespread drug abuse and racial tensions. Reflecting on this period, Krulak would report it as a “bad, bad time for the Corps.” Krulak welcomed a call for Marine Corps “exceptionalism” made by Marine Commandant Gen. Leonard F. Chapman Jr., and he would re-enforce this call throughout his own career.

Krulak’s emphasis on the human dimension was apparent when he asserted a philosophy of “equip the man” instead of “man the equipment.” Given his Vietnam service, he saw firsthand the disastrous results of Project 100,000, which allowed the recruitment of citizens of low intelligence who were otherwise prevented from joining the military. Project 100,000 participants required significantly more training resources, were more likely to be arrested, and, because they were disproportionately assigned as infantry soldiers, were more than twice as likely to die in combat. The disastrous program ran from 1966 to 1971 until it was abandoned for offering no tangible advantage to the US military. Knowing firsthand the importance of intelligent and educated Marines, Krulak required 95 percent of new recruits to be high school graduates, raising the standard from 90 percent. The increased focus on what Krulak described as “going after the elite of the elite” ensured Marines who were better able to adapt to the constantly evolving battlefield.

Krulak’s addition of a “crucible” at recruit training is still used to this day. This capstone event consists of a fifty-four-hour exercise where recruits march over forty miles and face a series of challenges including a leader-reaction course and a combat-assault course. With only two Meals Ready to Eat and a total of six hours of sleep during this period, this “crucible” is a character-building event that drives home the concept of Marine Corps “transformation.” When combined with constant reinforcement of the Corps’ enduring ethos of “honor, courage, and commitment” throughout their career, Marines are well-prepared to act acceptably when facing battlefield “moral quandaries.” By calling on Marines to live by the Corps’ values 24 hours a day, 7 days a week, this constant call to virtue can drastically reduce the risk of unacceptable behavior as Marines display their consummate commitment to their Corps.

The skills required of junior leaders have only increased since Krulak’s introduction of the three-block war metaphor. In 2006, as the wars in Iraq and Afghanistan were grinding on, Marine Maj. T.M. Scott wrote that in such complex operating environments servicemembers required additional training and education in “cultural sensitivity, media awareness, mediation skills, linguistic competence, mastery of sophisticated weapons and sensors, and the capacity for small group operations.” In an era of renewed great-power competition, even more will be required of junior leaders, and it is increasingly likely they will arrive on the battlefield without the required training and education for all the problems they may encounter. A logical solution for this problem is to prioritize the art of learning as a critical skill for strategic corporals. This would include supporting the essential practice of self-development.

While there are limitations in the three-block war as a metaphor, Krulak was correct in identifying leader development as the critical requirement for junior military leaders on the modern battlefield. Empowered and developed strategic corporals have demonstrated their value repeatedly during America’s post-9/11 wars. The strategic-corporal developmental philosophy produced junior leaders in the Marines who were fully developed and empowered through professional military education, provided with quality leadership examples, and constantly called to live the ethos of their Corps. These individuals possessed a greater understanding and mastery of the spectrum of force that could be applied to achieve mission goals. With superior development and greater abilities to find alternate solutions and select the most appropriate levels of force for a given situation, these leaders could achieve mission success while vastly reducing the risk of negative events that could adversely shift public opinion.

It is unfortunate that the underlying call for junior-leader development within the three-block war metaphor was and remains misunderstood outside the context of the Marine Corps. Krulak’s positive message was misinterpreted as a warning of tactical blunders leading to strategic defeat. As this negative misinterpretation of the strategic corporal grew, the concept became associated with only the toxic aspects and the leader-development components of Krulak’s metaphor were largely ignored. The legacy of the three-block war has been forever marred by events like Abu Ghraib and the soldiers responsible, who had not been prepared in accordance with Krulak’s vision of strategic corporals. While Krulak’s metaphor presented an intelligent junior leader, fully developed and optimized by mission command, the misinterpretations of his theory resulted in micromanagement of junior leaders out of fear of the “toxic” strategic corporal.

The operational focus of the military has now shifted to multi-domain operations, and while this concept revolves around a vision of the future battlefield that is starkly different from the landscape painted in Krulak’s three-block war, there remains a need for a solid developmental philosophy to create junior leaders capable of operating in complex environments and maximizing the use of mission command. The abandonment of the strategic-corporal developmental philosophy is tragic and has left a critical void in how other military branches approach the development of the human dimension in its members and leaders. All US military branches still need servicemembers who have been developed through high-quality professional military education, are virtue-driven, and have exceptional examples of battlefield leadership to emulate. It is time to re-educate our force on the original intent of Krulak’s strategic-corporal developmental philosophy and to best prepare for the twenty-first-century battlefield.


Dr. Franklin C. Annis is a National Guard officer and veteran of the Iraq War. He holds a doctorate in education in curriculum and teaching from Northcentral University. Dr. Annis hosts the Evolving Warfighter YouTube channel where he shares his research on military self-development.

The views expressed are those of the author and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.


Image credit: Lance Cpl. Cesar N. Contreras, US Marine Corps