Deliberate Practice and the Acquisition of Military Expertise


Lt. Col. Sebastian K. Welsh, MD, U.S. Army


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Naval Postgraduate School students participate in analytic wargames they designed to explore solutions for some of the Department of Defense’s most pressing national security concerns 3 June 2018 in Monterey, California

The study of history by military officers has been an oft-defended but difficult-to-justify part of professional military education (PME). Research on cultivating expertise provides evidence that studying military history offers a method for achieving expert military performance, particularly at war’s operational and strategic levels. Following America’s recent military misadventures in Iraq and Afghanistan, the question arises yet again. Why does such a technically and tactically adept force continue to lose wars?1 In the wake of Vietnam, Peter Paret and Colin Gray found a lack of strategic expertise as an answer.2 The world continues to face an increasingly complex strategic environment with the return of war to the European continent, great-power competition, and Chinese “unrestricted warfare.”3 The current approach to PME and training in the U.S. military generates an asymmetry in favor of tactical and technical expertise while failing to cultivate strategic expertise. This asymmetry primes current and future senior military leaders to excel at the tactical level of warfare while failing at the operational and strategic levels.

A definition of expertise is necessary to evaluate the usefulness of studying military history. Once expertise is defined, a discussion of various methods of obtaining expertise follows. American PME and training, historically and currently, create adequate tactical and technical expertise while failing to generate strategic experts. However, modern research on acquiring professional expertise shows that the deliberate practice of history and theory can help generate the proficiency necessary to execute successful military operations. Historical study is also low-cost and has no risk of injury compared to other military training methods. A career-long practice of critical analysis and writing can generate the hours of practice necessary to reach expert-level performance. Deliberate practice in studying history and theory is essential for developing world-class military experts in operational planning and strategy.

Defining Expertise

A clear definition is required to understand the value of military expertise in military operations. In On War, Carl von Clausewitz describes the makings of military “genius.”4 He includes intellect, the strength of mind, and quick recognition of the truth. His description of the coup d’oeil of a military genius presages a current understanding of expertise; however, Clausewitz, with an understanding appropriate to his time, believed these were inherited traits.5 He also includes several attributes, markers, and behaviors that were not elements of expert performance, such as the strength of character and physical courage.6 The intellectual gifts of Clausewitz’s military genius are better known today as expertise. Still, as Clausewitz defined it, the term military genius is too vague and covers additional characteristics that make it a broader definition than required for military expertise.

Field Manual 6-22

Malcolm Gladwell popularized professional expertise and expert performance in his book Outliers. He defined experts as those who have practiced a skill to an extreme degree or the “10,000-hour rule.”7 Using other literature on expertise, he determined that time applied to a craft defines expertise. Although it is undeniable that practice is part of creating an expert, practice time alone is not the definition of expertise. The definition of expert performance used in the literature varies depending on the domain under investigation.8 Researchers distinguish expert and nonexpert performance based on a subject’s speed, accuracy, and reproducibility while completing a task.9 Sight-reading a piece of music or solving chess puzzles are examples of functions an expert can do more quickly and accurately than a nonexpert. In military expertise, this begins to look like Clausewitz’s coup d’oeil.

Army Field Manual 6-22, Developing Leaders, defines expertise as “the specialized knowledge and skills developed from experience, training, and education.”10 This definition approaches military expertise in terms of the domain of knowledge. It states that expertise has only one component: possessing facts or understanding. With this definition, soldiers obtain expertise primarily by reading and regurgitating doctrine. The definition does not include a level of performance. The resulting expert would be nonfunctional outside a narrow set of predefined parameters. For example, a person may know a surgical procedure from reading a surgical text. Still, they could only be called an expert with practice, judgment, high proficiency in surgical skills, and repeatable exemplary performance. A combination of these definitions should result in a helpful definition to understand military expertise and investigate its attainment.

In this context, military expertise means mastery of knowledge and skills necessary to perform military tasks at an exceedingly high level. This definition allows an analysis of military tasks beyond tactics and battle drills that are already rigorously trained. Military functions at all levels of warfare, including operational and strategic, are implicit in the definition. A degree of proficiency delineates simply possessing a nascent skill or modicum of knowledge from an expert; for example, an introductory history course does not make a person a military history expert. A specific definition of military expertise now allows for investigating expertise acquisition methods.

Types of Practice

Deliberate practice. Anders Ericsson delineates various types of practice to understand their application in different professional domains. Deliberate practice is the practice designed by a teacher for a pupil.11 The pupil practices and receives feedback and correction from the teacher in real time. Studies on this form of practice generated Gladwell’s ten thousand-hour rule. Researchers studied musicians to determine how world-class expert performers trained to achieve that status.12 A critical point in deliberate practice is that the pupil practices with the intention of improving a skill. The teacher designs the practice for that student and corrects errors in real-time. The following is an example of deliberate practice in military history. A history teacher picks a case study appropriate to the student and articulates the case study’s goals. The student would analyze the case study and generate a written product as directed by the teacher. The teacher would then make suggestions and corrections for the student to improve understanding, analysis, and written products as the pupil practices. The relationship between Gerhard von Scharnhorst and Clausewitz gives an excellent example of a teacher-pupil dynamic that created a preeminent expert through deliberate practice.13

Purposeful practice. Purposeful practice is a solitary practice where an individual focuses on a particular performance aspect with intermittent or no feedback from a coach or teacher.14 Like deliberate practice, purposeful practice requires the intention of the individual to improve some part of their performance. Two key differences are the need for more outside guidance on the form of practice and the lack of feedback from a coach or teacher. Purposeful practice in conjunction with deliberate practice may increase reliable, superior performance. Still, the correlation is far less clear than with deliberate practice.15 An example of a military expert utilizing purposeful practice would be selecting and evaluating historical case studies without assistance in the selection and without feedback. The Army places most professional development into this category as self-development.16

Structured practice. Structured practice reflects the current approach to historical study at Command and General Staff College. Structured practice is a practice activity guided by a teacher for a group of students in group activities without individualization or tailoring for each member’s specific skill level.17 Structured practice allows for the training of a large group of people. The variation in pupils’ capabilities will result in challenges for some, while others benefit less. The instructor also delivers less specific feedback less frequently than in deliberate practice.

Naïve practice. Naïve practice is performing, as in work or play, for goals other than developing a skill.18 Naïve practice is essentially the on-the-job training that many soldiers receive. Although these activities are domain related, studies showed that this practice does not reliably lead to expert performance.19 Beyond PME, training and education in the U.S. Army frequently fall under naïve practice. Historical study or reading for fun would be classified as naïve practice as the goal is for enjoyment, not increasing a particular skill or domain-specific knowledge.

In the meta-analysis conducted by Ericsson, deliberate practice, purposeful practice, and structured practice are combined when estimating hours of practice, so for the remainder of this article, deliberate practice will mean any of these three activities.20 The researchers do not include naïve practice as the primary focus is not improving the skill.

Deliberate practice in sufficient quantity has created world-class expertise in diverse fields of complex behavioral performance.21 Therefore, the deliberate study of military history and theory can help generate the expertise necessary to execute successful military operations by improving the understanding of war’s operational and strategic levels. The amount of practice for expert performance remains immense at thousands of hours, depending on the domain.22 Even when conducted regularly, deliberate practice takes years of effort to achieve expertise. Most experts started deliberate practice in childhood or early adulthood. Professional violinists began between ages four and six, accumulating ten thousand hours of deliberate practice by around age twenty.23 Earlier starting age correlated with higher rates of attaining elite performance in multiple domains, including sports, chess, and music.24

Officer Training and Education

Practice in the military occupation begins with initial training and is periodic throughout a career in PME. Most training and education during the first half of a military career focuses on technical and tactical expertise.25 Military history as a form of practice does not begin until officers have practiced their craft for ten years or more. Strategic studies do not start in earnest until students attend the U.S. Army War College. The average age of a U.S. Army War College student is forty-five years old for the class of 2023.26 With diligent practice, these officers will achieve expert status at roughly sixty years old, assuming expertise acquisition occurs at the same rate in middle age as in childhood and adolescence (likely a flawed assumption). The late start in the deliberate study of history leads to a rapid learning curve that many officers will be unable to overcome for the remainder of their careers. The result is an officer corps that meets standards but rarely reaches reproducible expert performance in the domains that historical study benefits most-operational and strategic thinking.

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The deliberate study of military history and theory can help generate the expertise necessary to execute successful military operations by improving the understanding of war’s operational and strategic levels.

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Previous models of officer education recognized the benefits of studying history even without modern research on acquiring expertise. Scharnhorst refounded the Kriegsakademie (War Academy) to select and train highly skilled officers to complete the three-year curriculum to become the Prussian General Staff.27 This training generated expertise that paid reliable dividends throughout the nineteenth and early twentieth centuries. The Kriegsakademie, from its founding, incorporated historical studies, although not until 1826 did it incorporate many of Clausewitz’s suggestions for the curriculum to focus less on mathematics.28 The curriculum included six to seven hours of military and nonmilitary history a week, which over a three-year course of study, amounts to approximately one thousand hours.29 Not only is this a sizeable down payment of hours toward acquiring military expertise, but the course design also generated analysis in contrast to the U.S. Army’s equivalent school.

Contrasting the U.S. Army’s Command and General Staff School (CGSS) and the Kriegsakademie of the interwar period highlights the importance of cultivating expertise through deliberate practice. CGSS at the time consisted of a majority map and maneuver exercise with little room for student creativity or analysis.30 CGSS developed officers ready to manage a division but did not result in military expertise. Meanwhile, the Kriegsakademie presented challenging problems for individuals and small groups with direct feedback from instructors.31 These practitioners of the deliberate study of history made possible Gen. Hans von Seeckt’s fifty-seven committees and the diligent studies they created.32 Historical examples, mainly from the Prussian-German experience, show the benefits of historical analysis even in resource-constrained environments, such as existed under the Treaties of Tilsit and the Treaty of Versailles.

The U.S. Army also faces a resource-constrained environment in terms of funding, training time, and acceptable risk to forces in garrison. The most recent Field Manual 3-0, Operations, emphasizes the “human advantage” across the competition continuum.33 In preparation for large-scale combat operations, the U.S. Army has focused significant resources toward creating this human advantage at combat training centers (CTCs) for brigade-sized elements and Warfighter exercises to simulate division up to corps maneuvers.34 Focusing on tactical echelons up to the lower operational level of warfare shows priorities to maintain technical and tactical expertise. A continued focus throughout officers’ careers on technical and tactical expertise leaves a woefully short time for senior leaders to cultivate operational and strategic competence. Historical study, in comparison to CTC and Warfighter exercises, is an inexpensive endeavor. History funding for the Army is less than a twentieth of the annual budget for CTC rotations.35 Historical analysis also does not have the risk inherent in military training or combat operations.36 Even Clausewitz suffered a bayonet wound to the head.37 Additional guided hours in deliberate practice of history and theory can generate military expertise without decreasing the Army’s ability to fund the fight. It will allow students to stand on thousands of battlefields and consider limitless strategic implications with little cost and no risk of injury. These operational and strategic lessons can mitigate the lack of strategic expertise in the Army.

A model for deliberate military history and theory practice should focus on critical components of reading, critical analysis, thesis formation, and written argument. Practicing history this way develops several essential skills that find little practice outside the humanities. One of the initial skills is reading critically to determine the value of sources with conflicting opinions.38 A strategist must compare various sources and forms of intelligence, media, and political writings when considering ends, ways, and means. Critical analysis is necessary as many of these sources will have conflicting arguments or directly contradict each other. Historians compare, contrast, and weigh arguments from primary and secondary sources as a matter of course utilizing these arguments to generate a thesis.

Field Manual 6-22

Forming a thesis and defending it in writing exercises multiple high-level skills. Historical writing specifically requires inductive reasoning and a holistic view that is often lost in scientific writing. Utilizing this form of reasoning can help to counteract the asymmetry generated by a focus on deductive reasoning. Advanced writing utilizes logic and working memory beyond the superficial use in basic writing forms.39 Generating essential context in studying historical cases and underlying principles is essential to understanding how military operations fit in the larger geopolitical picture. No simulator or training center exists that can create the fidelity and degree of complexity of actual events. By practicing archival research, considering multiple sources, and writing, practitioners gain myriad benefits in critical thinking and problem-solving, including the decreased likelihood of holding unwarranted beliefs (e.g., false assumptions).40 With a model of deliberate practice outlined, a method of application throughout a military career will generate adequate hours of practice to obtain expertise.

Any program for cultivation of expertise would have to be voluntary. The requisite hours to achieve expertise far exceed the expectations and available hours for training in PME. Deliberate practice throughout a military career would begin with basic writing and logic instruction at initial training utilizing historical case studies as a foundation. The initial basic instruction is necessary because many high school and undergraduate programs do not achieve a basic level of writing proficiency.41 The initial training could begin at any point but would be of most benefit earlier in a career. Those officers and noncommissioned officers who complete initial instruction, intermittent seminars, and written assignments focused on long-term growth in the key skills of reading, analysis, thesis formation, and written argument would be assigned through an apprenticeship-style program with a historian guiding their progress. Through years of practice, lifelong learners would generate a portfolio of their work at multiple levels of warfare. The preparation would create capable writers who could easily exceed the written requirements of field grade and senior-level PME. Currently, the Command and General Staff Officer College has a history writing requirement of at most fifteen pages.42 The critical component in deliberate practice is its ongoing and progressive nature. PME currently occurs with years of skill atrophy followed by brief use in the educational setting before further atrophy until the next iteration. On-the-job use, or, as defined earlier, naïve practice, does not generate the progressive learning and development required for true expertise. Naïve practice does not have the feedback and focus on progression that deliberate practice, by definition, has. The career-long learning and practice of history and strategy could cultivate reading, critical analysis, thesis formation, and written argument, skills critical to strategic thought.

Literature does not exist showing that historical study improves strategic thought, per se. However, numerous military theorists upon whose work current U.S. military doctrine rest generated their ideas through historical study and inductive reasoning. B. H. Liddell Hart, in Strategy, summarizes his theories on strategy after a thorough discussion of the historical cases that generated his conclusions.43 Alfred T. Mahan and Sir Julian Corbett generated modern naval power theories from extensive historical study.44 The study of history is insufficient to create profound strategic thinkers, but it is necessary to grasp the concepts, taxonomies, and lexicon employed. Training and education currently focus on the consumption of doctrine and its application without the underlying context of how this doctrine came into existence and the larger background of the world in which it is to be applied. The characteristics of firepower focus, dependence on technology, and logistical excellence outlined by Colin Gray in “The American Way of War” require technical and tactical expertise.45 The focus on these characteristics minimizes strategy and history, creating, as Gray describes it, a “strategy deficit.”46 For this same reason, in Makers of Modern Strategy, Peter Paret, Gordon Alexander Craig, and Felix Gilbert argue that studying history and the narrative thread present in strategy is essential for understanding war.47 Current PME in the U.S. Army has shown no improvement from the interwar period and may have worsened regarding the deliberate practice of military history and theory.48 Command and General Staff Officer College dedicates fifty hours of classroom time.49 In 1992, Congressman Ike Skelton noted the minimal focus on studying history to develop strategic expertise, which amounted to fifty-one hours in 1988.50 Time dedicated to studying history and historical analysis does not meet the thousands of hours of practice documented in recent research on expertise acquisition. Numerous training opportunities occur to practice battle drills and tactics; however, no rotations exist at CTCs for the deliberate practice of understanding history and theory. The deliberate practice of historical study, beginning at initial training, would allow for thousands of hours of practice during a career. Expertise acquisition would occur earlier in an officer’s career and enhance understanding of the strategic environment.

With the current understanding of expertise acquisition, the problem and solution become readily apparent. If years of practice and thousands of hours of deliberate practice are required to achieve military expertise, then the U.S. Army cannot reliably create military experts. The result is a tactically excellent army without strategic expertise. This asymmetry in training to education worsens throughout a military career with the expectation that in a few years, with occasional PME opportunities, senior leaders can make up the deficit and become experts in fields they have not previously practiced. The study of military history and theory provides a process for the deliberate practice of essential skills at the operational and strategic levels creating military expertise. Clausewitz describes the study of military history as “an active ingredient of talent.”51 The current method of training military expertise in the U.S. Army lacks this critical ingredient.

The views expressed in this manuscript are those of the author and do not necessarily reflect the official policy of the U.S. Army, Department of Defense, or the U.S. government.


  1. Daniel P. Bolger, Why We Lost: A General’s Inside Account of the Iraq and Afghanistan Wars (Boston: Eamon Dolan/Houghton Mifflin Harcourt, 2014; Boston: Mariner Books, 2015). Citations refer to the Mariner edition.
  2. Colin Gray, “The American Way of War: Critique and Implications,” in Rethinking the Principles of War, ed. Anthony McIvor (Annapolis, MD: U.S. Naval Institute Press, 2012), 27; Peter Paret, Gordon Alexander Craig, and Felix Gilbert, eds., Makers of Modern Strategy: From Machiavelli to the Nuclear Age (Princeton, NJ: Princeton University Press, 1986), 7–8.
  3. Qiao Liang and Wang Xiangsui, Unrestricted Warfare (Beijing: PLA Literature and Arts Publishing House, 1999).
  4. Carl von Clausewitz, On War, ed. and trans. Michael Howard and Peter Paret (Princeton, NJ: Princeton University Press, 1976), 100–4.
  5. Ibid., 102.
  6. Ibid., 107.
  7. Malcolm Gladwell, Outliers: The Story of Success, 1st ed. (New York: Little, Brown, 2008), 38.
  8. Patricia A. Alexander, “The Development of Expertise: The Journey from Acclimation to Proficiency,” Educational Researcher 32, no. 8 (November 2003): 10–14,
  9. K. Anders Ericsson and Kyle W. Harwell, “Deliberate Practice and Proposed Limits on the Effects of Practice on the Acquisition of Expert Performance: Why the Original Definition Matters and Recommendations for Future Research,” Frontiers in Psychology 10 (24 October 2019): Article 2396,
  10. Field Manual (FM) 6-22, Developing Leaders (Washington, DC: U.S. Government Publishing Office [GPO], 2022), 4-25.
  11. Ericsson and Harwell, “Deliberate Practice and Proposed Limits,” 6.
  12. K Anders Ericsson, Ralf T. Krampe, and Clemens Tesch-Römer, “The Role of Deliberate Practice in the Acquisition of Expert Performance,” Psychological Review 100, no. 3 (1993): 363–406,
  13. Donald J. Stoker, Clausewitz: His Life and Work (New York: Oxford University Press, 2014).
  14. Ericsson and Harwell, “Deliberate Practice and Proposed Limits,” 6.
  15. Ibid., 9.
  16. FM 6-22, Developing Leaders, 3-1.
  17. Ericsson and Harwell, “Deliberate Practice and Proposed Limits,” 6.
  18. Ibid., 9.
  19. Ibid., 10–11.
  20. Ibid., 9.
  21. Ibid., 12.
  22. Ericsson, Krampe, and Tesch-Römer, “The Role of Deliberate Practice,” 379.
  23. Ibid.
  24. Ibid., 389.
  25. FM 6-22, Developing Leaders, 1-6.
  26. U.S. Army War College, Academic Programs Guide: Academic Year 2023 (Carlisle, PA: U.S. Army War College, 2023), 47.
  27. Spenser Wilkinson, The Brain of an Army: A Popular Account of the German General Staff, new ed. (London: Constable, 1913), 148.
  28. Stoker, Clausewitz, 257.
  29. Wilkinson, Brain of an Army, 162.
  30. Jörg Muth, Command Culture: Officer Education in the U.S. Army and the German Armed Forces, 1901–1940, and the Consequences for World War II, 1st ed. (Denton: University of North Texas Press, 2011), 131.
  31. Harlan N. Hartnass, “Report on the German General Staff School—1936,” American Embassy, Office of the Military Attaché, reprinted in H100: Syllabus and Book of Readings (Fort Leavenworth, KS: U.S. Army Command and General Staff College [USACGSC], July 2022), 353–56.
  32. Williamson Murray, “May 1940: Contingency and Fragility of the German RMA,” in The Dynamics of Military Revolution, 1300–2050, ed. MacGregor Knox and Williamson Murray (New York: Cambridge University Press, 2001), 158.
  33. FM 3-0, Operations (Washington, DC: U.S. GPO, 2022).
  34. Army Financial Management and Comptroller, Fiscal Year (FY) 2023 Budget Estimates, April 2022, Volume I: Operation and Maintenance, Army (Washington, DC: U.S. GPO, April 2022), 20, 23, 30,
  35. Ibid., 672.
  36. Hannah Fischer and Hibbah Kaileh, “Trends in Active-Duty Military Deaths from 2006 through 2021,” Congressional Research Service (CRS) In Focus 10899 (Washington, DC: CRS, 9 September 2022), 1,
  37. Stoker, Clausewitz, 290.
  38. Cynthia Shanahan, Timothy Shanahan, and Cynthia Misischia, “Analysis of Expert Readers in Three Disciplines: History, Mathematics, and Chemistry,” Journal of Literacy Research 43, no. 4 (2011): 393–429,
  39. Ronald T. Kellogg and Alison P. Whiteford, “Training Advanced Writing Skills: The Case for Deliberate Practice,” Educational Psychologist 44, no. 4 (October 2009): 250–66,
  40. Anne Collins McLaughlin and Alicia Ebbitt McGill, “Explicitly Teaching Critical Thinking Skills in a History Course,” Science and Education 26, no. 1-2 (March 2017): 93–105,
  41. Kellogg and Whiteford, “Training Advanced Writing Skills,” 250–51.
  42. Department of Military History, “Block Advance Sheet,” in H100: Syllabus and Book of Readings (Fort Leavenworth, KS: USACGSC, July 2022), 16; Department of Military History, “Block Advance Sheet,” in H400: Syllabus and Book of Readings (Fort Leavenworth, KS: USACGSC, July 2022), 15.
  43. B. H. Liddell Hart, Strategy: The Classic Book on Military Strategy, 2nd rev. ed. (New York: Meridian, 1991), 319–70.
  44. A. T. Mahan, The Influence of Sea Power upon History, 1660–1783, 12th ed. (Boston: Little, Brown, 1989); Julian Stafford Corbett and Eric J. Grove, Some Principles of Maritime Strategy (Annapolis, MD: U.S. Naval Institute Press, 1988).
  45. Gray, “The American War of War,” 30–33.
  46. Ibid., 34.
  47. Paret, Craig, and Gilbert, Makers of Modern Strategy.
  48. Muth, Command Culture, 131; Department of Defense, Summary of the National Defense Strategy of the United States of America: Sharpening the American Military’s Competitive Edge (Washington, DC: U.S. GPO, 2018), 8.
  49. H100: Syllabus and Book of Readings; H400: Syllabus and Book of Readings.
  50. Ike Skelton, “JPME: Are We There Yet?,” Military Review 72, no. 5 (May 1992): 6.
  51. Clausewitz, On War, 141.


Lt. Col. Sebastian K. Welsh, U.S. Army, is deputy commander for clinical services at 549th Hospital Center, Camp Humphreys, South Korea, with duty as the assistant chief of pediatric specialties at Tripler Army Medical Center in Honolulu. He holds a BS in clinical laboratory science from Saint Louis University; an MD from the Uniformed Services University of the Health Sciences, Bethesda, Maryland; and an MOS from Command and General Staff College, Leavenworth, Kansas. He is an assistant professor of pediatrics at the Uniformed Services University of the Health Sciences.


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