War

War is an armed conflict between the armed forces of states, or between governmental forces and armed groups. These groups have a clear chain of command and can keep up military operations. War can also happen between two such organized groups.

War usually involves a lot of violence and destruction, and people can be hurt or killed. It can use regular or irregular military forces. Wars usually have goals that are political, economic, or about land. Warfare refers to the common activities and features of types of war, or of wars in general. Total war is warfare that is not limited only to legitimate military targets. It can harm many civilians and other people who are not fighting, leading to many casualties.

War has changed in many ways over history. The pictures show examples from different times: the Stele of the Vultures from about 2500 BCE, the Battle of Hastings in 1066, the Retreat from Moscow in 1812, the Battle of the Somme in 1916, the Normandy landings in 1944, and the Atomic bombing of Nagasaki in 1945.

Since 1945, wars between great powers, territorial conquests and war declarations have declined in frequency. However, war in general has not necessarily become less common. Civil wars have increased in number since 1945.

Wars are increasingly guided by international humanitarian law, which sets rules to protect people. Battle deaths and casualties have declined, partly because of advances in military medicine. Several terms redirect here. For other uses, see War (disambiguation), Wars (disambiguation), Warring (disambiguation), Warfare (disambiguation) and Conflict zone (disambiguation).

Etymology

The English word war comes from the Old English words wyrre and werre, which were used in the 1100s. These came from the Old French word werre (guerre in modern French). That word came from the Frankish werra. Going back even further, it comes from the Proto-Germanic werzō, which meant 'mixture, confusion'.

The word is related to the Old Saxon werran and the Old High German werran. It is also related to the modern German verwirren, which means 'to confuse' or 'to bring into confusion'.

History

Main article: Military history

Experts do not agree on whether war was common in early human history or whether it started later, after people began farming or forming organized states. It is hard to know if war happened in the Paleolithic because few remains from that time have been found. Some sources say that many Middle and Upper Paleolithic groups were possibly egalitarian, meaning people had equal status, and they may have rarely or never fought organized wars with other groups. Signs of violent conflict seem to increase from around 10,000 years ago, in the Mesolithic period. American cultural anthropologist Raymond C. Kelly claimed that before 400,000 years ago, humans fought in ways similar to groups of chimpanzees, but later they preferred peaceful ties with neighbors. In his 1996 book War Before Civilization, Lawrence H. Keeley, a professor at the University of Illinois, says that about 90–95% of known societies in history fought at least sometimes, and many fought all the time. Keeley describes small raids and large raids. Because resources were scarce, defensive works were not a practical way to protect people from raids. William Rubinstein wrote that societies without writing were known for being very cruel. The Bronze Age is described as an important time when war became more common, with trained warriors and metal weapons like swords. Two other periods often named as times when war increased are the Axial Age and Modern Times. The invention of gunpowder, and its use in war, along with quick technological advances, brought big changes to war itself.

In Coercion, Capital, and European States, AD 990–1992, Charles Tilly argued that "war made the state, and the state made war." He meant that wars led to the creation of states, which then continued to fight wars. Tilly's theory of state formation is considered the leading idea in the study of how states formed. Since 1945, wars between great powers, territorial conquests and war declarations have declined in frequency. Wars have also increasingly been guided by international humanitarian law, which sets rules to protect people. Fewer people have been killed or injured in battles, partly because of better military medicine, even though weapons have become more advanced. According to Michael Spagat and William Thompson, wars between great powers in Western Europe have steadily declined since the 16th century. Joshua Goldstein, John Mueller and Steven Pinker have argued that war is in decline, while Bear F. Braumoeller has challenged such claims. However, civil wars have increased in number since 1945, and most fighting has been civil wars and uprisings. The major exceptions were the Korean War, the Indo-Pakistani War of 1971, the Iran–Iraq War, the Gulf War, the Eritrean–Ethiopian War, and the Russo-Ukrainian War.

Types of warfare

Main article: Types of war

Warfare can take many forms. Asymmetric warfare is used when belligerents have very different levels of military power or size. Biological warfare, also called germ warfare, uses harmful germs or poisons, such as bacteria, viruses, and fungi, against people, plants, or animals. It can use advanced technology, such as cluster munitions, or simple methods. Chemical warfare uses harmful chemicals in fighting. Poison gas, a chemical weapon, was mainly used during World War I. Cold warfare is a strong international rivalry without direct fighting, but with a constant threat of it. It may include economic warfare, political warfare, covert operations, espionage, cyberwarfare, or proxy wars. Conventional warfare is fighting between countries that does not use nuclear, biological, chemical, or radiological weapons, or uses them only in limited ways.

Cyberwarfare involves a nation or international organization attacking another nation's information systems. Insurgency is a rebellion against authority, in which irregular forces take up arms to change the existing political order. It can be opposed through counterinsurgency, which uses measures to protect the population, and through political and economic actions that weaken the rebels' claims. Information warfare involves large-scale attacks on information systems, including the computers and networks that support four critical infrastructures: the power grid, communications, financial, and transportation. Nuclear warfare uses nuclear weapons as the main, or a major, way of forcing an enemy to surrender. Radiological warfare involves deliberately spreading radiation poisoning or contamination in an area using radiological sources. Total war uses any means possible, ignores the laws of war, and places no limits on legitimate military targets. It uses weapons and tactics that can greatly affect civilian casualties, and it demands a war effort that requires major sacrifices from civilians. Unconventional warfare includes military and quasi-military operations other than conventional warfare. It may use secret actions such as subversion, diversion, sabotage, espionage, biowarfare, sanctions, propaganda, or guerrilla warfare.

Aims

Countries that are thinking about going to war, or about ending one, may set out war aims. These are the goals they hope to reach. Leaders can also use them to persuade people. War aims can show how determined a nation is. Fried describes war aims as "the desired territorial, economic, military or other benefits expected following successful conclusion of a war."

War aims can be tangible, such as gaining land, as in the German goal of Lebensraum in the first half of the 20th century. They can also be economic, such as getting trade deals, as in the Anglo-Dutch Wars. Some war aims are intangible, like building up credibility or reputation. War aims can be explicit, shown in published policy decisions. They can also be implicit, found in meeting notes, memos, and instructions. Positive war aims try to achieve something good. Negative war aims try to stop something unwanted from happening. War aims can change during a conflict. They may eventually become "peace conditions," the minimum conditions under which a state may stop fighting.

Effects

Main article: Effects of war

Global deaths in conflicts since the year 1400

When a war happens, one or more areas become war zones. Daily life is disrupted there, and travel can be hard. No one knows the exact number of people killed by war, and estimates vary widely. Ian Morris and Azar Gat have both estimated how many people were killed by war across history. A list collects death estimates for many wars. Some air defence and military robots are used to try to keep people safer. World War II is the deadliest war in history, and the Mongol conquests were also extremely deadly. War often damages buildings, harms the environment, and leads to famine. It can force many people to leave their homes, and prisoners of war and civilians are sometimes treated very badly. Some wars also bring propaganda and higher profits for weapons manufacturers.

Soldiers in combat often suffer harm to their minds and bodies. This can include sadness, posttraumatic stress disorder, sickness, injury, and death. Civilians also suffer greatly. Wars cause many people to lose their lives, and they destroy homes, food, and other things people need. This can lead to famine, sickness, and death among the civilian population. During the Thirty Years' War, the population of the Holy Roman Empire became much smaller. People may also be treated very cruelly during wars. Wars also make life harder and can hurt people's health. After a war ends, losing nations are sometimes required to pay war reparations. Land may also be given to the winners, as happened with Alsace-Lorraine. Wars often hurt the economies of the countries involved. The Great Depression ended as nations made more war materials during World War II.

Theories of motivation

Experts do not agree on why wars happen. Military thinker Carl von Clausewitz said that every age has its own kind of war. Some thinkers look at human feelings and behavior, including revenge. Others look at how humans may have evolved. Some believe that group conflict appears in many animals, such as chimpanzees. Economic ideas suggest that wars often start when countries compete for natural resources and markets. Some ideas focus on leaders, such as Napoleon and Hitler. These leaders are said to have wanted war, and ordinary people were pulled into it.

Other ideas focus on population and resources. Thomas Malthus wrote that populations keep growing until they are limited by war, disease, or famine. Marxist theory says that wars between powerful countries come from competition for resources and markets under capitalism. Rationalist ideas say that countries would often be better off avoiding war. Sometimes, though, they misjudge each other's strength. Political scientists study the causes of war in three ways: across the whole international system, across societies, and across individual people.

Ethics

People have debated whether war is right or wrong for thousands of years. The just war theory says there are two main parts to ethics in war. The first is jus ad bellum (right to war), which covers when an authority may declare war on another nation. The second is jus in bello (right in war), which covers the rules for fighting a war. A just war must be declared by a lawful authority. It must have a fair and serious cause and good intentions. It should have a reasonable chance of success, be a last resort, and use means that match its goals.

Jus in bello has two main ideas. Proportionality means using only as much force as is needed and right for the goals and the injustice suffered. Discrimination means keeping fighters, who may be targeted, separate from non-combatants, who may not be. Breaking these rules can cost a just side its legitimacy. The just war theory helped shape the United Nations and international law's rules on legitimate war. Lewis Coser, an American sociologist, argued that conflict can help balance and maintain a society rather than only disrupting it.

Limiting and stopping

Main article: Anti-war movement

Religious groups have long opposed war or tried to limit it. The Second Vatican Council wrote a document called Gaudiem et Spes. It says that attacks meant to destroy whole cities or large areas, and the people living there, are a crime against God and humanity.

Anti-war movements have existed for every major war of the 20th century. These included World War I, World War II, and the Vietnam War. In the 21st century, people around the world joined anti-war movements against the United States invasion of Afghanistan and Iraq. People in Europe, Asia, and the United States also protested the War in Afghanistan.

Pauses

Main articles: Ceasefire and Armistice

During a war, the sides may agree to pause. A ceasefire is a stop in fighting. Each side agrees to stop its attacks, often with help from a third party. It may be part of a formal treaty or an informal agreement between opposing forces. A ceasefire can be temporary or can last a long time. An armistice is different. It is a formal end to a war, while a ceasefire may only be a short stop.

The main goal of a ceasefire is to stop violence, but it can have other purposes. It may help with short-term needs, such as bringing aid to people who need it. It may also make a conflict less harmful or help settle a disagreement peacefully. Sometimes a side uses a ceasefire to gain an advantage, such as getting ready to fight again. This creates bargaining problems that can make ceasefires harder to carry out and keep. Ceasefires are more likely to last when there are safe zones without soldiers, troops move back, and a third party watches over the agreement (such as peacekeeping). They also last longer when steps are taken to stop small accidents from growing into bigger conflicts.