Winning the War of the Flea

Lessons from Guerrilla Warfare

Lieutenant Colonel Robert M. Cassidy, U.S. Army

Download the PDF Download the PDF

Indians encamped outside a frontier fort. (Inset) Major General George Crook.

Analogically, the guerrilla fights the war of the flea, and his military enemy suffers the dog’s disadvantages: too much to defend; too small, ubiquitous, and agile an enemy to come to grips with. If the war continues long enough—this is the theory—the dog succumbs to exhaustion and anemia without ever having found anything on which to close its jaws or to rake with its claws.

–Robert Taber1

Counterguerrilla warfare, or the “war against the flea,” is more difficult than operations against enemies who fight according to the conventional paradigm. America’s enemies in the Global War on Terrorism, including those connected to “the base” (al-Qaeda), are fighting the war of the flea in Iraq and Afghanistan. Employing terror to attack the United States at home and abroad, they strive to disrupt coalition efforts by using guerrilla tactics and bombings to protract the war in Iraq and elsewhere and to erode America’s will to persevere.

The war on al-Qaeda and its surrogates can be viewed as a global counterinsurgency in which the United States and its coalition partners endeavor to isolate and eradicate the base and other networked terrorist groups who seek sanctuary, support, and recruits in ungoverned or poorly governed areas where the humiliated and the have-nots struggle to survive. The U.S. military’s preference for the big-war paradigm has heretofore impeded the Army from seriously studying counterinsurgency operations. As a result, the Army has failed to incorporate many lessons from successful counterinsurgency operations. Because countering insurgents and terrorists remains a central mission of the U.S. military for the foreseeable future, it is better to incorporate lessons learned than to relearn lessons during combat.

With the right mindset and with a broader, deeper knowledge of lessons from previous successes, the war against the flea can be won. The Army has successfully fought counterguerrilla wars. However, the contradiction emanating from America’s unsuccessful expedition in Vietnam is that, because the experience was perceived as anathema to the U.S. military’s core culture, hard lessons learned there about fighting guerrillas were not preserved or rooted in the Army’s institutional memory. The U.S. military culture’s efforts to exorcise the specter of Vietnam, epitomized by the shibboleth “No More Vietnams,” also precluded the Army, as an institution, from actually learning from those lessons.

The Army’s intellectual renaissance after Vietnam has focused almost exclusively on the culturally preferred, conventional big-war paradigm.2 Army doctrine conceals the term “counterinsurgency” under the innocuous categories of stability operations and foreign internal defense. Many lessons exist in the U.S. military’s historical experience with small wars, but the lessons from Vietnam are the most voluminous—and the least read. The end of the Cold War has made it improbable that conventional or symmetric war will ever again be the norm, and the Army is making genuine efforts to transform its culture and mindset. Senior civilian and military leaders of the Army and the Office of the Secretary of Defense realized a change in military culture was a precondition for innovative approaches to a more complex security landscape in which adversaries adopt unorthodox strategies and tactics to undermine U.S. technological superiority in an orthodox or conventional war.

Military culture is the sum total of embedded beliefs and attitudes within a military organization that shape that organization’s preference on when and how military force should be used. Cultural propensities can block innovation in ways of warfare that are outside perceived central or core roles. A preference for a big-war paradigm has hitherto been an obstacle to learning how to fight guerrillas.3 The Army must analyze U.S. involvement in, and the nature of, small wars, insurgencies, and counterinsurgencies. Without some sense of historical continuity, American soldiers will have to relearn the lessons of history each time they face a new small war.4

The Indian Wars and Beating Guerrillas

The Indian wars of the 19th century provide some counterinsurgency lessons and demonstrate that the guiding principles for fighting insurgents can endure the test of time. Without codified doctrine and little institutional memory for fighting guerrillas, the late-19th century Army had to adapt to Indian tactics on the fly. A loose body of principles for fighting an unorthodox enemy emerged from the Indian wars, including the following:

  • Ensure close civil-military coordination of the pacification effort.
  • Provide firm but fair paternalistic governance.
  • Reform the economic and educational spheres.

Good treatment of prisoners, attention to Indian grievances, and avoiding killing women and children (a lesson learned by trial and error) were also regarded as fundamental to any long-term solution. The Army’s most skilled Indian fighter, General George Crook, developed the tactic of inserting small teams from friendly Apache tribes into insurgent Apache groups to neutralize and psychologically unhinge them and to sap their will. This technique emerged in one form or another in the Philippines, during the Banana Wars, and during the Vietnam war.

Andrew J. Birtle’s U.S. Army Counterinsurgency and Contingency Operations Doctrine 1860-1941, one of the better books on the Army’s role in the Indian wars, describes Captain Randolph B. Marcy’s The Prairie Traveler: A Handbook for Overland Expeditions as “perhaps the single most important work on the conduct of frontier expeditions published under the aegis of the War Department.”5 In essence, Marcy’s book was a how-to manual for packing, traveling, tracking, and bivouacking on the plains and a primer on fighting the Indians. In formulating pacification principles, Marcy looked at his own experiences on the frontier as well as Turkish and French experiences pacifying North Africa. He arrived at the following conclusions:

  • Over-dispersion strips the counterinsurgent force of initiative, increases its vulnerability, and saps its morale.
  • Mobility is imperative. (Mounting infantry on mules was one way of increasing mobility during that era.)
  • Surprise is paramount. Employing mobile mounted forces at night to surprise the enemy at dawn was the best way to counter the elusive Indians. The Prairie Traveler conveys one principal message that is still relevant: soldiers must possess the self-reliance, the individuality, and the rapid mobility of the insurgent, along with conventional military discipline.6
Filipino scouts and their officer during the Philippine Insurrection. (<em>Inset</em>) Brigadier General John J. Pershing.

The Philippine Insurgency (U.S. Army)

During the Philippine Insurgency from 1899 to 1902, the U.S. military achieved victory and established the foundation for an amicable future between the United States and the Philippines. Guerrilla war scholar Anthony James Joes notes, “There were no screaming jets accidentally bombing helpless villages, no B-52s, no napalm, no artillery barrages, no collateral damage. Instead, the Americans conducted a decentralized war of small mobile units armed mainly with rifles and aided by native Filipinos, hunting guerrillas who were increasingly isolated both by the indifference or hostility of much of the population and by the concentration of scattered peasant groups into larger settlements.”7

The U.S. military learned to—

  • Avoid big-unit search-and-destroy missions because they were counterproductive in a coun-terinsurgency context.
  • Maximize the use of indigenous scouts and paramilitary forces to increase and sustain decentralized patrolling.
  • Mobilize popular support by focusing on the improvement of hospitals, schools, and infrastructure.

The U.S. military enhanced the legitimacy of the Filipino regime it supported by allowing former insurgents to organize antiregime political parties. In an award-winning study, Max Boot ascribes U.S. success in the Philippines to a measured application of incentives and disincentives: the U.S. military used aggressive patrolling and force to pursue and crush insurgents, but it treated captured rebels well and generated goodwill among the population by running schools and hospitals and improving sanitation.8

Brigadier General John J. Pershing returned to the Philippines to serve as military governor of the Moro Province from 1909 to 1913. To pacify the Moros, he applied the lessons he had learned as a captain during the Philippine Insurrection. He established a Philippine constabulary of loyal indigenous troops and did not attempt to apply military force by itself. He “felt that an understanding of Moro customs and habits was essential in successfully dealing with them, and he went to extraordinary lengths to understand Moro society and culture.”9

NVA defectors read one of the 15 million safe-conduct passes dropped over areas where North Vietnamese and Viet Cong forces were operating.

Pershing also comprehended the need to have U.S. forces involved at the grassroots level. He understood the sociopolitical aspects, and he realized military goals sometimes had to be subordinated to them. Boot says, “He scattered small detachments of soldiers throughout the interior, to guarantee peaceful existence of those tribes that wanted to raise hemp, produce timber, or farm.”10 During Pershing’s first tour in the Philippines as a captain, he was allowed inside the Forbidden Kingdom, and the Moros made him a Moro Datu, an honor not granted to any other white man.11

Latin America and the Caribbean

While the Army has had to relearn how to fight every new insurgency, the U.S. Marine Corps captured its guerrilla warfare experiences and distilled them in its 1940 Small Wars Manual.12 The lessons Marines learned leading Nicaragua Guardia Nacional patrols against Augusto “Cesar” Sandino’s guerrillas might well have served as the foundation for the Marines’ counterinsurgency operations in Vietnam.

From experience in Haiti, the Dominican Republic, and Nicaragua during the first part of the 20th century, the Marines learned that, unlike conventional war, a small war presents no defined or linear battle area or theater of operations. The manual maintains that delay in the use of force might be interpreted as weakness, but the brutal use of force is not appropriate either: “In small wars, tolerance, sympathy, and kindness should be the keynote to our relationship with the mass of the population.”13

The manual urges U.S. forces to employ as many indigenous troops as practical early on to restore law and order and stresses the importance of focusing on the social, economic, and political development of the people more than on material destruction. The manual also underscores the importance of aggressive patrolling, population security, and denial of sanctuary to the insurgents. An overarching principle, though, is not to fight small wars with big-war methods. The goal is to gain results with the least application of force and minimum loss of civilian (noncombatant) life.

Lessons from Vietnam

When most Americans reflect on Vietnam, they probably think of General William C. Westmore­land, the Americanization of the war, large-scale search-and-­destroy missions, and battles of attrition. There was another war, however, a war of counterinsurgency and pacification in which many Special Forces (SF), Marines, and other advisers employed small-war methods with some degree of success.

When General Creighton Abrams became the commander of U.S. Military Assistance Command, Vietnam (MACV) in 1968, he put an end to the two-war approach by adopting a one-war focus on pacification, although it was too late by then to recover the political support for the war squandered during the Westmoreland years. Still, Abrams’ unified strategy to clear and hold the countryside by pacifying and securing the population met with much success. Abrams based his approach on A Program for the Pacification and Long-Term Development of South Vietnam, a study prepared by the Army staff in 1966.14 The Special Forces’ experiences in organizing Civilian Irregular Defense Groups (CIDG), the Combined Action Program (CAP), and Abrams’ expansion of the Civil Operations and Revolutionary (later Rural) Development and Support (CORDS) pacification effort offer valuable lessons for current and future counterinsurgency operations.

For much of the Vietnam war, the 5th SF Group trained and led CIDG mobile strike forces and reconnaissance companies manned by indigenous ethnic minority tribes from mountain and border regions. These forces conducted small-unit reconnaissance patrols and defended their home bases in the border areas from Viet Cong (VC) and regular North Vietnamese Army (NVA) units.

From 1966 to 1967, U.S. field commanders increasingly employed SF-led units in long-range reconnaissance missions or as economy-of-force security elements for regular units. Other CIDG-type forces, called mobile guerrilla forces, raided enemy base areas and employed hit-and-run guerrilla tactics against regular enemy units. The SF also recruited extensively among Nung tribes for the Delta, Sigma, and Omega units, which were SF-led reconnaissance and reaction forces.

The CIDG program made a significant contribution to the war effort. The approximately 2,500 soldiers assigned to the 5th SF Group essentially raised and led an army of 50,000 tribal fighters to operate in some of the most difficult and dangerous terrain in Vietnam. CIDG patrols of border infiltration areas provided reliable tactical intelligence, and the CIDG secured populations in areas that might have been otherwise conceded to the enemy.15

The Marine Corps’ CAP was another initiative that significantly improved the U.S. military’s capacity to secure the population and to acquire better tactical intelligence. Under CAP, a Marine rifle squad assisted a platoon of local indigenous forces. This combined Marine and indigenous platoon trained, patrolled, defended, and lived together in the platoon’s village. CAP’s missions were to—

  • Destroy VC infrastructure within the village or hamlet area of responsibility.
  • Provide public security and help maintain law and order.
  • Protect friendly infrastructure.
  • Protect bases and communications within the villages and hamlets.
  • Organize indigenous intelligence nets.
  • Participate in civic action and conduct propaganda against the VC.

Civic action played an important role in efforts to destroy the VC because it brought important intelligence about enemy activity from the local population. Because CAP protected the villagers from reprisals, it was ideal for acquiring intelligence from locals. The Marines’ focus on pacifying highly populated areas prevented guerrillas from coercing the local population into providing rice, intelligence, and sanctuary. The Marines would clear and hold a village in this way and then expand the secured area.

CAP units accounted for 7.6 percent of the enemy killed while representing only 1.5 percent of the Marines in Vietnam. CAP employed U.S. troops and leadership in an economy of force while maximizing the use of indigenous troops. A modest investment of U.S. forces at the village level yielded major improvements in local security and intelligence.16

Even though CORDS was integrated under MACV in 1967, Abrams and William Colby, Director of CORDS, expanded the program and invested it with good people and resources. Under Abrams’ one-war approach to Vietnam, CORDS provided oversight of the pacification effort. After 1968, Abrams and Colby made CORDS and pacification the principal effort. A rejuvenated civil and rural development program provided increased support, advisers, and fundings to police and territorial forces (regional forces and popular forces). The new emphasis on rural development allowed military and civilian advisers from the U.S. Agency for International Development to work better with their Vietnamese counterparts at the provincial and village levels to improve local security and develop infrastructure.

Eliminating the VC infrastructure was critical to pacification. Colby’s approach—the Accelerated Pacification Campaign—included the Phoenix (Phuong Hoang) program to neutralize VC infrastructure. Although the program received some bad press, its use of former VC and indigenous Provisional Reconnaissance Units to root out the enemy’s secret underground network was quite effective. The CORDS Accelerated Pacification Campaign focused on territorial security, neutralizing VC infrastructure, and supporting self-defense and self-government at the local level.17

Begun in November 1968, the Accelerated Pacification Campaign helped the Government of Vietnam (GVN) control most of the countryside by late 1970. The “other war”—pacification—had been practically won. The four million members of the People’s Self-Defense Force, armed with some 600,000 weapons, were examples of the population’s commitment to the GVN. Regional and popular forces also experienced significant improvements. Under CORDS, these forces provided close-in security for the rural population. Although imperfect and quantitative, MACV’s Hamlet Evaluation System showed that between 1969 and 1970 CORDS efforts contributed to the pacification of 2,600 hamlets (three million people).

Other more practical measures of the Accelerated Pacification Campaign’s success were a reduction in VC extortion and recruitment in South Vietnam and a decrease in food provisions taken from the villagers. To be fair, however, other factors also contributed to GVN control of the countryside. The Tet Offensive in January 1968 and Mini-Tet in May 1968 resulted in devastating losses to VC forces in the south, allowing MACV/CORDS to intensify pacification. Moreover, the enemy’s brutal methods (including mass murder in Hue) during Tet shocked South Vietnam’s civilian population and created a willingness to accept more aggressive conscription. Ho Chi Minh’s death in September 1969 might have also had an effect on the quality and direction of NVA leadership.18

CIDG, CAP, and CORDS expanded the quality and quantity of the forces available to conduct coun-terinsurgency, improved small-unit patrolling, and consequently improved the content, scope, and quality of intelligence. One can only speculate how the war might have gone if CAP and CIDG had been integrated under MACV and CORDS in 1964, with Abrams and Colby in the lead. The lessons of these programs are relevant today. Improving the quantity and capabilities of indigenous forces; establishing an integrated and unified civil-military approach; and increasing the security of the population continue to be central goals in Afghanistan and Iraq.19

These Vietnam-era programs were not without flaws, however. Two persistent problems plagued the CIDG program. Hostility between the South Vietnamese and ethnic minority groups comprising the CIDG strike forces impeded U.S. efforts to have Republic of Vietnam Special Forces take over the program. As a result, the 5th SF Group failed to develop an effective counterpart organization.

Even the Marines’ CAPs were not completely effective. In some instances the effects of CAPs were transitory at best because the villagers became dependent on them for security. In other cases, especially before Abrams emphasized training popular forces, poor equipment and training made them miserably incapable of defending the villages without the Marines. What’s more, until 1967, CORDS was not integrated under MACV, which seriously undermined any prospect of actually achieving unity of effort and purpose. Abrams’ influence resolved this by allowing MACV to oversee CORDS as well as regular military formations.20

Staving Off Defeat

Today, the Army is prosecuting three coun-terinsurgencies and learning to adapt to insurgency and counterinsurgency in contact. This is a genuinely compelling reason to expand the Army’s depth and breadth of knowledge about counterinsurgency operations. The U.S. military, particularly the Army, must develop a culture that emphasizes stability operations and counterinsurgency among its core missions.

The global war against the flea will be protracted, but it will be won. The rule of law, democracy, and civilization will prevail over chaos, theocracy, and barbarism. As Mao Tse Tung said, “Although guerrilla operations are the cosmic trap of military strategy, the muck, the quicksand in which a technologically superior military machine bogs down in time-consuming futility, they cannot in and of themselves win wars. Like mud, they can stave off defeat, but, like mud, they cannot bring victory.”21


  1. Robert Taber, The War of the Flea: Guerrilla Warfare in Theory and Practice (New York: Lyle Stuart, Inc., 1965), 27-28.
  2. See Robert M. Cassidy, “Prophets or Praetorians: The Uptonian Paradox and the Powell Corollary,” Parameters (Autumn 2003): 132-33.
  3. For a short discussion on military culture and big-war preferences, see Cassidy, Russia in Afghanistan and Chechnya: Military Strategic Culture and the Paradoxes of Asymmetric Conflict (Carlisle, PA: U.S. Army Strategic Studies Institute, 2003), 8, 54-60.
  4. Sam C. Sarkesian, America’s Forgotten Wars: The Counterrevolutionary Past and Lessons for the Future (Westport, CT: Greenwood Press, 1984), 245.
  5. Andrew J. Birtle, U.S. Army Counterinsurgency and Contingency Operations Doctrine 1860-1941 (Washington, DC: U.S. Army Center of Military History, 1988), 55-92; CPT Randolph B. Marcy, The Prairie Traveler: A Handbook in Overland Expeditions (Bedford, MA: Applewood Books, January 1988).
  6. Birtle, 64-65.
  7. Anthony James Joes, America and Guerrilla Warfare (Lexington: University Press of Kentucky, 2000), 120-23.
  8. Max Boot, Savage Wars of Peace: Small Wars and the Rise of American Power (New York: Basic Books, 2003), 126.
  9. Sarkesian, 178-180.
  10. Ibid.
  11. Ibid.
  12. U.S. Marine Corps (USMC), Small Wars Manual (Washington, DC: Government Printing Office, 1940), 1-1-1-31; USMC Combat Development Command, Small Wars (Quantico, VA: U.S. Marines Corps, 2004 Draft), iii-iv; Boot, “A Century of Small Wars Shows They Can Be Won,” New York Times Week in Review, 6 July 2003.
  13. Ibid.
  14. U.S. Department of the Army, A Program for the Pacification and Long-Term Development of South Vietnam (Washington, DC: U.S. Department of Defense, 1966), 1-9; Lewis Sorley, A Better War (New York: Harcourt Brace and Company, 1999), 10-125.
  15. Jeffrey J. Clarke, Advice and Support: The Final Years (Washington, DC: U.S. Army Center of Military History, 1988), 196-207.
  16. Frank Pelli, “Insurgency, Counterinsurgency, and the Marines in Vietnam,” unpublished paper, USMC Command and Staff College, Quantico, VA, 1990, 13-16; Brooks R. Brewington, “Combined Action Platoons: A Strategy for Peace Enforcement,” unpublished paper, USMC Command and Staff College, Quantico, VA, 1996, 13-19.
  17. Sorley, 22-23, 64-67.
  18. Ibid., 64-67, 72-73, and 217-24.
  19. Ibid., 1.
  20. Clarke, 207; Keith F. Kopets, “The Combined Action Program: Vietnam,” Military Review (July-August 2002): 78-79.
  21. Mao Tse-Tung, cited in E.L. Katzenbach, Jr., “Time, Space, and Will: The Political-Military Views of Mao Tse-Tung” in The Guerrilla and How to Fight Him, ed. T.N. Greene (New York: Praeger, 1962), 17.


Lieutenant Colonel Robert M. Cassidy, U.S. Army, is a member of the U.S. Army Europe Commanding General’s Initiatives Group, Heidelberg, Germany. He received a B.A. from Fitchburg State College, an M.A. from Boston University, and an M.A.L.D. and a Ph.D. from the Fletcher School of Law and Diplomacy. He has served in various command and staff positions in the continental United States and Germany. His article “Renaissance of the Attack Helicopter in the Close Fight” appeared in the July-August 2003 issue of Military Review.


Back to Top

September-October 2004