Asymmetric warfare can describe a conflict in which the resources of two belligerents differ in essence and in the struggle, interact and attempt to exploit each other's characteristic weaknesses. Such struggles often involve strategies and tactics of unconventional warfare, the weaker combatants attempting to use strategy to offset deficiencies in quantity or quality. Such strategies may not necessarily be militarized. This is in contrast to symmetric warfare, where two powers have similar military power and resources and rely on tactics that are similar overall, differing only in details and execution.
The term is also frequently used to describe what is also called "guerrilla warfare", "insurgency", "terrorism", "counterinsurgency", and "counterterrorism", essentially violent conflict between a formal military and an informal, less equipped and supported, undermanned but resilient opponent.
- Definition and differences 1
- Strategic basis 2
- Tactical basis 3
- Use of terrain 4
- War by proxy 5
- Asymmetric warfare and terrorism 6
- American Revolutionary War 7.1
- American Civil War 7.2
- Philippine-American War 7.3
20th century 7.4
- Second Boer War 7.4.1
- World War I 7.4.2
- Between the World Wars 7.4.3
World War II 7.4.4
- Britain 220.127.116.11
- United States 18.104.22.168
After World War II 7.5
- Cold War 7.5.1
- Cold War examples of proxy wars 7.5.2
21st century 7.6
- Israel/Palestinians 7.6.1
- Sri Lanka 7.6.2
- Kashmir 7.6.3
- Iraq 7.6.4
- Syria 7.6.5
- See also 8
- References 9
Further reading 10
- Bibliographies 10.1
- Books 10.2
- 10.3 Articles and papers
Definition and differences
The popularity of the term dates from Andrew J. R. Mack's 1975 article "Why Big Nations Lose Small Wars" in World Politics, in which "asymmetric" referred simply to a significant disparity in power between opposing actors in a conflict. "Power," in this sense, is broadly understood to mean material power, such as a large army, sophisticated weapons, an advanced economy, and so on. Mack's analysis was largely ignored in its day, but the end of the Cold War sparked renewed interest among academics. By the late 1990s, new research building on Mack's insights was beginning to mature, and, after 2004, the U.S. military began once again to seriously consider the problems associated with asymmetric warfare.
Discussion since 2004 has been complicated by the tendency of academic and military communities to use the term in different ways, and by its close association with guerrilla warfare, insurgency, terrorism, counterinsurgency, and counterterrorism. Military authors tend to use the term "asymmetric" to refer to the indirect nature of the strategies many weak actors adopt, or even to the nature of the adversary itself (e.g., "asymmetric adversaries can be expected to ...") rather than to the correlation of forces.
Academic authors tend to focus more on explaining the puzzle of weak actor victory in war: if "power," conventionally understood, conduces to victory in war, then how is the victory of the "weak" over the "strong" explained? Key explanations include (1) strategic interaction; (2) willingness of the weak to suffer more or bear higher costs; (3) external support of weak actors; (4) reluctance to escalate violence on the part of strong actors; (5) internal group dynamics and (6) inflated strong actor war aims. Asymmetric conflicts include both interstate and civil wars, and over the past two hundred years have generally been won by strong actors. Since 1950, however, weak actors have won a majority of all asymmetric conflicts.
In most conventional warfare, the belligerents deploy forces of a similar type and the outcome can be predicted by the quantity of the opposing forces or by their quality, for example better command and control of their forces (c2). There are times where this is not true because the composition or strategy of the forces makes it impossible for either side to close in battle with the other. An example of this is the standoff between the continental land forces of the French army and the maritime forces of the United Kingdom's Royal Navy during the French Revolutionary and Napoleonic Wars. In the words of Admiral Jervis during the campaigns of 1801, "I do not say, my Lords, that the French will not come. I say only they will not come by sea", and a confrontation that Napoleon Bonaparte described as that between the elephant and the whale.
The tactical success of asymmetric warfare is dependent on at least some of the following assumptions:
- One side can have a technological advantage which outweighs the numerical advantage of the enemy; the decisive English longbow at the Battle of Crécy is an example.
- Technological inferiority usually is cancelled by more vulnerable infrastructure which can be targeted with devastating results. Destruction of multiple electric lines, roads or water supply systems in highly populated areas could have devastating effects on economy and morale, while the weaker side may not have these structures at all.
- Training and tactics as well as technology can prove decisive and allow a smaller force to overcome a much larger one. For example, for several centuries the Greek hoplite's (heavy infantry) use of phalanx made them far superior to their enemies. The Battle of Thermopylae, which also involved good use of terrain, is a well-known example.
- If the inferior power is in a position of self-defense; i.e., under attack or occupation, it may be possible to use unconventional tactics, such as hit-and-run and selective battles in which the superior power is weaker, as an effective means of harassment without violating the laws of war. Perhaps the classical historical examples of this doctrine may be found in the American Revolutionary War, movements in World War II, such as the French Resistance and Soviet and Yugoslav partisans. Against democratic aggressor nations, this strategy can be used to play on the electorate's patience with the conflict (as in the Vietnam War, and others since) provoking protests, and consequent disputes among elected legislators.
- If the inferior power is in an aggressive position, however, and/or turns to tactics prohibited by the laws of war (jus in bello), its success depends on the superior power's refraining from like tactics. For example, the law of land warfare prohibits the use of a flag of truce or clearly marked medical vehicles as cover for an attack or ambush, but an asymmetric combatant using this prohibited tactic to its advantage depends on the superior power's obedience to the corresponding law. Similarly, laws of warfare prohibit combatants from using civilian settlements, populations or facilities as military bases, but when an inferior power uses this tactic, it depends on the premise that the superior power will respect the law that the other is violating, and will not attack that civilian target, or if they do the propaganda advantage will outweigh the material loss. As seen in most conflicts of the 20th and 21st centuries, this is highly unlikely as the propaganda advantage has always outweighed adherence to international law, especially by dominating sides of any conflict.
Use of terrain
Terrain can be used as a force multiplier by the smaller force and as a force inhibitor against the larger force. Such terrain is called difficult terrain.
The contour of the land is an aid to the army; sizing up opponents to determine victory, assessing dangers and distance. "Those who do battle without knowing these will lose." ― Sun Tzu, The Art of War
The guerrillas must move amongst the people as a fish swims in the sea. ― Mao Zedong.
A good example of this type of strategy is the Battle of Thermopylae, where the narrow terrain of a defile was used to funnel the Persian forces, who were numerically superior, to a point where they could not use their size as an advantage.
For a detailed description of the advantages for the weaker force in the use of built-up areas when engaging in asymmetric warfare, see the article on urban warfare.
War by proxy
Where asymmetric warfare is carried out (generally covertly) by allegedly non-governmental actors who are connected to or sympathetic to a particular nation's (the "state actor's") interest, it may be deemed war by proxy. This is typically done to give deniability to the state actor. The deniability can be important to keep the state actor from being tainted by the actions, to allow the state actor to negotiate in apparent good faith by claiming they are not responsible for the actions of parties who are merely sympathizers, or to avoid being accused of belligerent actions or war crimes. If proof emerges of the true extent of the state actor's involvement, this strategy can backfire; for example see Iran-contra and Philip Agee.
Asymmetric warfare and terrorism
There are two different viewpoints on the relationship between asymmetric warfare and terrorism. In the modern context, asymmetric warfare is increasingly considered a component of fourth generation warfare. When practiced outside the laws of war, it is often defined as terrorism, though rarely by its practitioners or their supporters. For example, terrorists often use women and children as human shields, which practise is not considered either moral or part of traditional symmetrical warfare.
The other view is that asymmetric warfare does not coincide with terrorism. The use of terror by the much lesser Mongol forces in the creation and control of the Mongol empire could be viewed as asymmetric warfare. The other is the use of state terrorism by the superior Nazi forces in the Balkans, in an attempt to suppress the resistance movement.
American Revolutionary War
From its initiation, the American Revolutionary War was, necessarily, a showcase for asymmetric techniques. In the 1920s, Harold Murdock of Boston attempted to solve the puzzle of the first shots fired on Lexington Green, and came to the suspicion that the few score militia men who gathered before sunrise to await the arrival of hundreds of well-prepared British soldiers were sent specifically to provoke an incident which could be used for propaganda purposes. The return of the British force to Boston following the search operations at Concord was subject to constant skirmishing, using partisan forces gathered from communities all along the route, making maximum use of the terrain (particularly trees and stone field walls) to overcome the limitations of their weapons- muskets with an effective range of only about 50–70 metres. Throughout the war, skirmishing tactics against British troops on the move continued to be a key factor in the Patriots' success; however, they may also have encouraged the occasional incidents, particularly in the later stages, where British troops used alleged surrender violations as a justification for killing large numbers of captives (e.g., Waxhaw and Groton Heights).
Another feature of the long march from Concord was the urban warfare technique of using buildings along the route as additional cover for snipers. When revolutionary forces forced their way into Norfolk, Virginia, and used waterfront buildings as cover for shots at British vessels out in the river, the response of destruction of those buildings was ingeniously used to the advantage of the rebels, who encouraged the spread of fire throughout the largely Loyalist town, and spread propaganda blaming it on the British. Shortly afterwards they destroyed the remaining houses, on the grounds that they might provide cover for British soldiers. On the subject of propaganda, it should be borne in mind that, contrary to the impression given in the popular American film The Patriot, British forces never adopted a popular response to partisan-style asymmetric warfare — retribution massacres of groups selected on a semi-random basis from the population at large.
The rebels also adopted a form of asymmetric sea warfare, by using small, fast vessels to avoid the Royal Navy, and capturing or sinking large numbers of merchant ships; however the British responded by issuing letters of marque permitting private armed vessels to undertake reciprocal attacks on enemy shipping. John Paul Jones became notorious in Britain for his expedition from France in the little sloop of war Ranger in April 1778, during which, in addition to his attacks on merchant shipping, he made two landings on British soil. The effect of these raids, particularly when coupled with his capture of the Royal Navy's HMS Drake — the first such success in British waters, but not Jones's last — was to force the British government to increase resources for coastal defence, and to create a climate of fear among the British public which was subsequently fed by press reports of his preparations for the 1779 Bonhomme Richard mission.
From 1776, the conflict turned increasingly into a proxy war on behalf of France, following a strategy proposed in the 1760s but initially resisted by the idealistic young King Louis XVI, who came to the throne at the age of 19 a few months before Lexington. France also encouraged proxy wars against the British in India, but ultimately drove itself to the brink of state bankruptcy by entering the war(s) directly, on several fronts throughout the world.
American Civil War
- Bryant, G. J. "Asymmetric Warfare: The British Experience in Eighteenth-Century India," Journal of Military History (2004) 68#2 pp 431–469. in Project Muse
- Ivan Arreguin-Toft, "How the Weak Win Wars: A Theory of Asymmetric Conflict", International Security, Vol. 26, No. 1 (Summer 2001), pp. 93–128.
- J. Paul Dunne, et al., "Managing Asymmetric Conflict," Oxford Economic Papers, Vol. 58 (2006), pp. 183–208.
- Fowler, C. A. "Bert" (March 2006). "Asymmetric Warfare: A Primer".
- Marcus Corbin Reshaping the Military for Asymmetric Warfare CDI website October 5, 2001.
- Vincent J. Goulding, Jr. Back to the Future with Asymmetric Warfare at the Wayback Machine (archived March 10, 2001) From Parameters, Winter 2000–01, pp. 21–30.
- Andrew J.R. Mack, "Why Big Nations Lose Small Wars: The Politics of Asymmetric Conflict", World Politics, Vol. 27, No. 2 (January 1975), pp. 175–200.
- Montgomery C. Meigs Unorthodox Thoughts about Asymmetric Warfare (PDF)
- Richard Norton-Taylor Asymmetric Warfare: Military Planners Are Only Beginning to Grasp the Implications of September 11 for Future Deterrence Strategy, in The Guardian, October 3, 2001
- Michael Novak, "Asymmetrical Warfare" & Just War: A Moral Obligation in NRO, February 10, 2003
- Toni Pfanner, "Asymmetrical Warfare from the Perspective of Humanitarian Law and Humanitarian Action", International Review of the Red Cross Vol. 87 No. 857 (March 2005), p. 149–174.
- Sullivan, Patricia. 2007. "War Aims and War Outcomes: Why Powerful States Lose Limited Wars", Journal of Conflict Resolution, 51 (3):496–524.
- Jonathan B. Tucker Asymmetric Warfare, a 6-page analysis, Summer 1999.
- Asymmetry and other fables, Jane's Defence Weekly, 18 August 2006
- David Buffaloe 'Defining Asymmetric Warfare'  September 2006
- Gates Assails Pentagon on Resources for Battlefields Washington Post April 22, 2008
- Mandel, Robert. "Reassessing Victory in Warfare." Armed Forces & Society, Jul 2007; vol. 33: pp. 461–495. http://afs.sagepub.com/cgi/content/abstract/33/4/461
- Mandel, Robert. "The Wartime Utility of Precision Versus Brute Force in Weaponry." Armed Forces & Society, Jan 2004; vol. 30: pp. 171–201. http://afs.sagepub.com/cgi/content/abstract/30/2/171
Articles and papers
- Arreguin-Toft, Ivan, How the Weak Win Wars: A Theory of Asymmetric Conflict, New York & Cambridge, Cambridge University Press, 2005 ISBN 0-521-54869-1
- Beckett, I. F. W. (15 September 2009). Encyclopedia of Guerrilla Warfare (Hardcover). Santa Barbara, California: Abc-Clio Inc. ISBN 9780874369298* Barnett, Roger W., Asymmetrical Warfare: Today's Challenge to U.S. Military Power, Washington D.C., Brassey's, 2003 ISBN 1-57488-563-4
- T.V. Paul, Asymmetric Conflicts: War Initiation by Weaker Powers, New York, Cambridge University Press, 1994, ISBN 0-521-45117-5
- J. Schroefl, Political Asymmetries in the Era of Globalization, Peter Lang, 2007, ISBN 978-3-631-56820-0
- Kaplan, Robert D., Warrior Politics: Why Leadership Demands a Pagan Ethos, New York, Vintage, 2003 ISBN 0-375-72627-6
- Merom, Gil, How Democracies Lose Small Wars, New York, Cambridge, 2003 ISBN 0-521-80403-5
- Metz, Steven and Douglas V. Johnson II, Asymmetry and U.S. Military Strategy: Definition, Background, and Strategic Concepts, Carlisle Barracks, Strategic Studies Institute/U.S. Army War College, 2001 ISBN 1-58487-041-9 
- J. Schroefl, S.M. Cox, T. Pankratz, Winning the Asymmetric War: Political, Social and Military Responses, Peter Lang, 2009, ISBN 978-3-631-57249-8
- Record, Jeffrey, Beating Goliath: Why Insurgencies Win, Washington D.C., Potomac Books, 2007, ISBN 978-1-59797-090-7
- Gagliano Giuseppe,Introduzione alla conflittualita' non convenzionale,New Press,2001
- Sobelman, Daniel, 'New Rules of the Game: Israel and Hizbollah after the Withdrawal from Lebanon, Tel-Aviv University, Jaffee Center for Strategic Studies, 2004 [www.inss.org.il/upload/(FILE)1190276456.pdf]
- Sobelman, Daniel, 'Hizbollah—from Terror to Resistance: Towards a National Defence Strategy, in Clive Jones and Sergio Catignani (eds.), Israel and Hizbollah An Asymmetric Conflict in Historical and Comparative Perspective,Routledge, 2010 (pp. 49–66)
- Compiled by Joan T. Phillips Bibliographer at Air University Library: A Bibliography of Asymmetric Warfare, August 2005.
- Asymmetric Warfare and the Revolution in Military Affairs (RMA) Debate sponsored by the Project on Defense Alternatives
- Tomes, Robert (Spring 2004). "Relearning Counterinsurgency Warfare". Parameters (US Army War College).
- Stepanova, E. 2008 Terrorism in asymmetrical conflict: SIPRI Report 23 (
- Zhao, et al. (2 October 2009). "Anomalously Slow Attrition Times for Asymmetric Populations with Internal Group Dynamics". Physical Review Letters 103, 148701 (2009) (APS).
- Arreguín-Toft, Ivan. "How the weak win wars - A theory of asymmetric conflict". Retrieved 17 September 2012.
- Andidora, Ronald (2000). Iron Admirals: Naval Leadership in the Twentieth Century. Greenwood Publishing Group. p. 3.
- Nicolson, Adam (2005). Men of Honor: Trafalgar and the making of the English Hero. HarperCollins. p. 73.
- Reshaping the military for asymmetric warfare Center for Defense Information
- William C. Banks. 2011. New Battlefields, Old Laws: Critical Debates on Asymmetric Warfare. Columbia University Press. isbn 0231526563
- Toutellot, A.B. "Harold Murdock's "The Nineteenth of April 1775" American Heritage Magazine Vol 10 Issue 5 August 1959
- Bicheno, Hugh (2003). Rebels & Redcoats. London: HarperCollins.
- Rapley, Rob (Writer, Producer, Director) (2012). "The Abolitionists". The American Experience. Season 24. Episode 9, 10, 11. Transcript. PBS. http://www.pbs.org/wgbh/americanexperience/films/abolitionists/player/.
- T.J. Stiles, "Jesse James: Last Rebel of the Civil War", 2002
- Border War Sesquicentennial proceedings at Lawrence, Kan., August 2013
- Chris Bray, The Media and GI Joe, in Reason (Feb 2002)
- Oxford English Dictionary
- Anonymous (Michael Scheuer), Imperial Hubris - Why the West is Losing the War on Terrorism, Washington DC, Brassey's (2004) ISBN 1-57488-849-8, Chap. 2
- "Hamas claims responsibility for attack". 6 May 2009. Retrieved 2009-05-06.
- "'"Hamas admits it DID use schools and hospitals in Gaza Strip as 'human shields' to launch rocket attacks on Israel - but claims it was 'mistake. 16 September 2014. Retrieved 2014-11-11.
- McCarthy, Rory (1 January 2008). "Death toll in Arab-Israeli conflict fell in 2007". London: The Guardian. Retrieved 2008-02-18.
- "Several killed in Syria car bombings". BBC News. 5 November 2012.
- "Syrian rebels emboldened after assassinations". CBS News. 19 July 2012.
- Civilian casualty ratio
- Fourth generation warfare
- Guerrilla warfare
- Irregular military
- List of guerrillas
- Low intensity conflict
- Military use of children
- Millennium Challenge
- People's war
- Partisan (military)
- Political Warfare
- Reagan Doctrine
- Resistance movement
- Unconventional warfare
- Unrestricted Warfare
- War amongst the people
- War on Terror
- "Yank" Levy
Much of the 2012-2013 Syrian civil war has been fought asymmetrically. The Syrian National Coalition along with the Mujahideen and Kurdish Democratic Union Party, has been engaging with the forces of the Syrian government through asymmetric means. The conflict has seen large-scale asymmetric warfare across the country, with the forces opposed to the government unable to engage symmetrically with the Syrian government so other tactics such as suicide bombings and targeted assassinations have been put to effective use.
The victory by the US-led coalition forces in the 1991 Persian Gulf War and the 2003 invasion of Iraq, demonstrated that training, tactics and technology can provide overwhelming victories in the field of battle during modern conventional warfare. After Saddam Hussein's regime was removed from power, the Iraq campaign moved into a different type of asymmetric warfare where the coalition's use of superior conventional warfare training, tactics and technology were of much less use against continued opposition from the various partisan groups operating inside Iraq.
The Sri Lankan Civil War, which raged on and off from 1983 to 2009, between the Sri Lankan government and the Liberation Tigers of Tamil Eelam (LTTE) saw large-scale asymmetric warfare. The war started as an insurgency and progressed to a large-scale conflict with the mixture of guerrilla and conventional warfare. The LTTE pioneered the use of suicide bombing and perfected it with the use of male/female suicide bombers both on and off battlefield; use of explosive-filled boats for suicide attacks on military shipping; use of light aircraft targeting military installations.
.suicide bombing and  use of civilian structures and civilian shields for military attacks, The
Likewise, the war between the mujahideen and the Red Army during the Soviet war in of Afghanistan has been claimed as the source of the term "asymmetric warfare", although this war occurred years after Mack wrote of "asymmetric conflict," it is notable that the term became well known in the West only in the 1990s. The aid given by the U.S. to the mujahadeen during the war was only covert at the tactical level, the Reagan Administration told the world that it was helping the "freedom-loving people of Afghanistan". This proxy war was aided by many countries including the USA against the USSR during the Cold War. It was considered cost effective and politically successful, as it gave the USSR a military defeat which was a contributing factor to its collapse.
In Southeast Asia, specifically Vietnam, the Viet Cong and other communist insurgencies engaged in asymmetrical guerilla warfare with France, at first, then, later, the United States during the period of the Vietnam War.
Cold War examples of proxy wars
The end of World War II established the two most powerful victors, the United States of America (USA, or just the United States) and the Union of Soviet Socialist Republics (USSR, or just the Soviet Union) as the two dominant world superpowers.
- United States Military Assistance Command Studies and Observations Group (US MAC-V SOG) in Vietnam
- United States support of the Nicaraguan Contras
After World War II
- Office of Strategic Services (OSS)
- China Burma India Theatre: Merrill's Marauders and OSS Detachment 101
- British Commandos and European coastal raids. German countermeasures and the notorious Commando Order
- Long Range Desert Group and the Special Air Service in Africa and later in Europe.
- South East Asian Theatre: Wingate, Chindits, Force 136, V Force
- Special Operations Executive (SOE)
- British Armed Forces against the Provisional Irish Republican Army in the Northern Campaign
- Philippine resistance against Japan - Philippines - During the Japanese occupation in World War II, there was an extensive Philippine resistance movement, which opposed the Japanese with active underground and guerrilla activity that increased over the years.
- Winter War – Finland opposed an invasion by the Soviet Union
- Soviet partisans – resistance movement which fought in the German occupied parts of the Soviet Union.
- Warsaw Uprising – Poland (Home Army, Armia Krajowa) rose up against the German occupation.
- Germany in Yugoslavia, 1941–45 (Germany vs. Tito's Partisans and Mihailović's Chetniks).
World War II
- Abd el-Krim led resistance in Morocco from 1920 to 1924 against French and Spanish colonial armies ten times as strong as the guerilla force, led by General Philippe Pétain.
- Europe, fought against Benito Mussolini's regime in northeast Italy.
- Anglo-Irish War (Irish War of Independence) fought between the Irish Republican Army and the Black and Tans/Auxiliaries. Lloyd George (British Prime Minister at the time) attempted to persuade other nations that it was not a war by refusing to use the army and using the Black and Tans instead but the conflict was conducted as an asymmetric guerrilla war and was registered as a war with the League of Nations by the Irish Free State.
Between the World Wars
- Lawrence of Arabia and British support for the Arab uprising against the Ottoman Empire. The Ottomans were the stronger power, the Arabs the weaker.
- Austria-Hungary vs. Serbia, August 1914. Austria-Hungary was the stronger power, Serbia the weaker.
- Germany vs. Belgium, August 1914. Germany was the stronger power, Belgium the weaker.
World War I
The Boer commando raids deep into the Jan Smuts, resonated throughout the century as the British and others adopted and adapted the tactics used by the Boer commandos in later conflicts.
Asymmetric warfare featured prominently during the Second Boer War. After an initial phase, which was fought by both sides as a conventional war, the British captured Johannesburg, the Boers' largest city, and captured the capitals of the two Boer Republics. The British then expected the Boers to accept peace as dictated by the victors in the traditional European way. However instead of capitulating, the Boers fought a protracted guerrilla war. Between twenty and thirty thousand Boer commandos were only defeated after the British brought to bear four hundred and fifty thousand troops, about ten times as many as were used in the conventional phase of the war. During this phase the British introduced internment in concentration camps for the Boer civilian population and also implemented a scorched earth policy. Later, the British began using blockhouses built within machine gun range of one another and flanked by barbed wire to slow the Boers' movement across the countryside and block paths to valuable targets. Such tactics eventually evolved into today's counter insurgency tactics.
Second Boer War
The Philippine–American War (Filipino/Tagalog: Digmaang Pilipino-Amerikano) (1899–1902) was an armed conflict between the United States and Filipino revolutionaries. Estimates of the Filipino forces vary between 100,000 to 1,000,000, with tens of thousands of auxiliaries. Lack of weapons and ammunition was a significant impediment to the Filipinos, so most of the forces were only armed with bolo knives, bows and arrows, spears and other primitive weapons that, in practice, proved vastly inferior to U.S. firepower. The goal, or end-state, sought by the First Philippine Republic was a sovereign, independent, socially stable Philippines led by the ilustrado (intellectual) oligarchy. Local chieftains, landowners, and businessmen were the principales who controlled local politics. The war was strongest when illustrados, principales, and peasants were unified in opposition to annexation. The peasants, who provided the bulk of guerrilla manpower, had interests different from their illustrado leaders and the principales of their villages. Coupled with the ethnic and geographic fragmentation, unity was a daunting task. The challenge for Aguinaldo and his generals was to sustain unified Filipino public opposition; this was the revolutionaries' strategic center of gravity. The Filipino operational center of gravity was the ability to sustain its force of 100,000 irregulars in the field. The Filipino general Francisco Macabulos described the Filipinos' war aim as, "not to vanquish the U.S. Army but to inflict on them constant losses." They initially sought to use conventional tactics and an increasing toll of U.S. casualties to contribute to McKinley's defeat in the 1900 presidential election. Their hope was that as President the avowedly anti-imperialist future Secretary of state William Jennings Bryan would withdraw from the Philippines. They pursued this short-term goal with guerrilla tactics better suited to a protracted struggle. While targeting McKinley motivated the revolutionaries in the short term, his victory demoralized them and convinced many undecided Filipinos that the United States would not depart precipitously. For most of 1899, the revolutionary leadership had viewed guerrilla warfare strategically only as a tactical option of final recourse, not as a means of operation which better suited their disadvantaged situation. On November 13, 1899, Emilio Aguinaldo decreed that guerrilla war would henceforth be the strategy. This made American occupation of the Philippine archipelago all the more difficult over the next few years. In fact, during just the first four months of the guerrilla war, the Americans had nearly 500 casualties. The Philippine Revolutionary Army began staging bloody ambushes and raids, such as the guerrilla victories at Paye, Catubig, Makahambus, Pulang Lupa, Balangiga and Mabitac. At first, it even seemed as if the Filipinos would fight the Americans to a stalemate and force them to withdraw. This was even considered by President McKinley at the beginning of the phase. The shift to guerrilla warfare drove the US Army to adopt counter-insurgency tactics. Civilians were given identification and forced into concentration camps with a publicly announced deadline after which all persons found outside of camps without identification would be shot on sight. Thousands of civilians died in these camps due to poor conditions.