The Nineteenth century strategist Carl von Clausewitz argued that ‘the fundamental nature of war is immutable. The characteristics or form of war typical in any particular age might change, but the essential nature of war could not. This distinction carries significant weight and holds considerable merit. As the course of international history and relations progresses, technological advancements, changes in operational and tactical strategy, and different international makeups have altered the way wars are conducted and the way in which they are fought. The underlying causes of and reasons for war, however, have remained the same throughout history, thereby affirming Clausewitz’s assertions.

Since the beginning of the ‘Westphalian’ era of international relations, warfare has experienced a number of periods of differing techniques, technologies, and strategies. The analyst William Lind described these periods as the ‘four generations’ of warfare. The ‘first generation’ of warfare is defined broadly as one of muskets and line and column tactics. Battles were formal and the battlefield orderly, with competing armies facing each other in open fields and firing in rank. Many of the distinguishing factors of the idea of the ‘military’, such as uniforms, ranks, and saluting, are products of this generation. Beginning in the middle of the 19th century, however, the introduction of rifled muskets, magazine-based ammunition and rapid-fire weapons made the application of lines and columns obsolete and, eventually, suicidal. The ‘second generation’ of warfare was one which applied mass firepower, most of which involved indirect artillery fire, and a defensive-based mentality. The First World War, with its intricate trench systems and static, defensive-based fronts, exemplified the second generation. The introduction of tanks, aircraft, and armored vehicles, intended to break the stalemate of the western front, brought about the ‘third generation’ of warfare. This generation was based on speed, surprise, initiative and decentralization of command. The Second World War was fought during this generation, and the German ‘Blitzkrieg’ doctrine of swift attacks, individual initiative, and encirclements was the prime example of the application of the ideas of this generation. The ‘fourth generation’ of warfare, which the modern world is transitioning into, is one where the state loses monopoly over war. Lind argues that state militaries find themselves fighting non-state opponents, such as Al-Qaeda, Hezbollah, or the FARC, more often than one another in this generation of warfare. Furthermore, victory on the battlefield in this generation does not carry the same operational weight as it did in those prior, and rather victory can be determined by destroying the opponent’s political or societal will to fight as opposed to defeating his armies on the field.

Other forms of warfare have remained constant throughout these generations. The prime example of this is asymmetrical warfare, where one side faces an overpowering, better equipped, and/or more technologically advanced foe by engaging in guerrilla warfare. Tactics for this form of warfare include ambushing opponents, surprise raids, sabotage, and targeted killings. Although asymmetrical warfare has been a sustained component of warfare through the ages (while conventional warfare has changed considerably in technique and operational strategy), the technologies utilized in asymmetrical warfare have changed in powerful ways. Modern guerrillas utilize weaponry such as IEDS (improvised explosive devises) to destroy armored vehicles and portable anti-aircraft weapons to down helicopters and fighter aircraft. The fact that these weapons are often easy to acquire, cheap to make, yet devastating in effect presents a large challenge to the conventional force they are used against. Additionally, fighters in an asymmetrical war can, and do, now utilize elements of modern society against their foe. For example, Al-Qaeda used commercial aircraft to attack the World Trade Centers in New York on 9/11. Organizations or fighters can utilize the internet to spread their ideology, recruit to their cause (oftentimes within their foe’s country), spread information on weapon-building and utilization, and even hack or disrupt important electronic services with devastating effect.

The characteristics and forms of war have thus changed through the ages, as evidenced by the various ‘generations’ of war and military strategy and the consistent improvement and changes in technology. While these facets of war have changed, however, the underlying causes of and reasons for war have not. Clausewitz argued that war was the ‘continuation of politics by other means’. He further contended that war ‘is thus an act of force to compel our enemy to do our will’. By these assertions he meant that war was a tool used by the state to both further act on it positions in international politics and to force the opponent to bend and submit to those positions. By defeating an enemy, a state can impose its will, whatever that will may be, upon it, and therefore further its position in the international arena. This definition of war, which explains its ‘essential nature’, has remained steady throughout the history of war and conflict since the beginning of the Westphalian era.

This definition of the nature of war is backed empirically by the examples provided in major wars that have occurred since the treaty of Westphalia in 1648. The War of the Spanish Succession and War of the Austrian Succession in the early 18th century were fought by its participants with the intention of instilling a specific monarch (and thus ruling family) over another. The victors of these wars accomplished their will by putting their choice of monarch on the throne, and thus furthered their political position in an international environment where ruling families controlled great amounts of international clout and power. The Seven Year’s war was a conflict over colonial territory, a major source of power, prestige, and wealth during the 18th century, and saw the alliance under the United Kingdom gain considerable swaths of French territory in the Americas. Through this victory, British international power was increased, and thus its political clout too increased. The American Revolution saw the United States attempting to create a separate political entity from the United Kingdom, and the war was thus an extension of political and domestic disputes between the colonists and their mother country. The American victory saw the U.K. bend to the will of the American people and granted them sovereignty. The Napoleonic Wars saw an emergent France attempting to spread ‘liberal’ ideology and increase its empire, and thus its political position on the world stage. The ultimate defeat of France made her concede to the Coalition’s will of returning to a pre-Napoleonic Europe, both ideologically and in borders. The American Civil War saw the extension of domestic disputes and politics into military conflict, with the Confederacy attempting to succeed from the Union over the issues of state rights and slavery, along with others. Again, the Union’s victory coincided with the enforcing of their will for the return to a united nation. The First World War and Second World War saw the attempt of Imperial and Nazi Germany to form larger and more powerful ’empires’ and thus be dominant political powers, and the victory of the Allies in both wars saw their will for the dismantlement of these empires (and, they hoped, the destruction of the German war machine) enacted. The American wars in Korea and Vietnam were extensions of its political goal of containing the spread of communism, and the ultimate failure of the US in Vietnam enabled the Communists to gain political control of the country. Finally, American wars in Afghanistan and Iraq saw its will for the toppling of the Taliban and Hussein regimes complete, and these were in turn due to the extension of the American ‘neo-con’ political viewpoint that the establishment of democracies in the Middle-East would stabilize the region and counter the threat of terrorism. Even non-state actors, such as Al-Qaeda, hold political motivations when conducting war with its foes. For example, they sought the removal of American troops from the Middle East and the extension of Islamist principles into Middle Eastern politics and societies. By attacking the United State and attempting to demoralize and terrorize its populace, it was simply attempting to enact this political will. Therefore, even while the world transitions into this ‘fourth generation’ of warfare against non-state actors, the underlying nature of war still remains the same. While this list of wars is not nearly comprehensive for the period of time between the modern era and 1648, the general trends shown in this list exemplify Clausewitz’s assertion that the nature of war is immutable despite changing characteristics of war. In each case, the participants were acting with a political reason and position in mind, and the victors enacted their will on the loser to further or accomplish that position.

Clausewitz asserted that the fundamental nature of war was immutable, despite the changing characteristics of war. While technologies, strategies, and even participants in wars change with the times, the underlying nature of war, where one state attempts to enforce its will upon another in order to accomplish its political goals, does not. Major wars throughout different eras of history, which all experienced different tactics, strategies, technologies, and applications of war, shared this fundamental facet. In each case, despite the different application of war, the fact that the victor enacted its will upon the loser and that the belligerents used war as an extension of its political agenda remains the same. Because of this, Clausewitz’s assertions are affirmed.