Usually, a war is waged by a country or group of countries against an opposing country with the goal of achieving an objective through the use of force. Wars can also be fought within a country in the form of civil conflict between different countries or different groups within a country. Wars have been a part of human history for thousands of years and have become increasingly destructive as industrialization and technology have advanced.
There is rarely one clear cause of conflict and ultimately war. The causes of war are usually numerous, and several causes of conflict can be intricately intertwined. Over the years, many theories have been put forth as to why wars happen, and some of the great experimental minds have offered their take on the subject.
Economic gain is the first cause of wars. Wars are often caused by one country's desire to take control of another country's wealth. Whether or not there may be other reasons for war, most conflicts almost always have an economic motive behind them, even if the stated purpose of wars is presented to the public as something nobler. In pre-industrial times, the gains desired by a warring country might be precious materials such as gold and silver or livestock such as cattle and horses. In modern times, the resources hoped for from war take the form of things like oil, minerals, or materials used in manufacturing. Some scientists believe that as the world's population increases and basic resources become scarcer, wars will increasingly be fought over such fundamental things as water and food. Historical examples of wars fought for economic gain are the Anglo-Indian Wars between 1766 and 1849. The Anglo-Indian Wars were a series of wars between the British East India Company and various Indian states. These wars led to the establishment of British colonial rule in India, which gave Britain unlimited access to the exotic and valuable resources native to the Indian continent.
Secondly, territorial conquest is the cause of war. A country may decide that it needs more land for both agricultural use and other purposes. Territory can also be used as ‘buffer zones’ between two hostile enemies, associated with buffer zones are proxy wars. These are conflicts that are conducted indirectly between opposing forces in a third country. Each power supports the side that best suits its logistical, military, and economic aspects. Proxy wars of interest were especially common during the Cold War. A historical example of wars fought for territorial gain is the Mexican-American War between 1846 and 1848. This war began after the annexation of Texas, with Mexico still claiming the land as its own. The US fought Mexico, keeping Texas and incorporating it as a state. Another example is the Serbo-Bulgarian War of 1885-1886, in which Bulgaria and Serbia fought over a small border town after moving a river that formed the border between the countries. And, of course, the Arab-Israeli War, or the ‘Six-Day War’, which took the territories of the West Bank, including East Jerusalem, from Jordan.
Thirdly, religion is also the main cause of conflicts and wars. Religious conflicts often have very deep roots. They can lie dormant for decades, only to reappear later. Religious wars can often be related to other causes of conflict, such as nationalism or revenge for a perceived historical loss in the past, while different religions fighting against each other can be the cause of war, for example in different places within the same religion. Fighting Protestants and Catholics or Sunnis and Shiites against each other can lead to war. A historical example of wars fought for religion is the Crusades between 1095-1291, the aim of which was to expel Islam and spread Christianity. The Thirty Years' War (1618-1648) is another example, where Holy Roman Emperor Ferdinand 11 tried to impose Roman Catholicism on the people of his domains, and a faction of Protestants from the north banded together, sparking the war. Historical examples of wars fought for religion also include the Lebanese Civil War (1975-1990), primarily sparked by conflicts between the Sunni Muslim, Shiite Muslim, and Christian Lebanese population, the Yugoslav Wars (1991-1995), which were fought between the Orthodox Catholic and Muslim population of former Yugoslavia, and the Second Sudanese Civil War (1983-2005), caused by the choice of the Muslim-centered government to impose Sharia law on non-Muslim southerners.
The fourth cause of war is nationalism. Nationalism in this context essentially means trying to prove that your country is superior to another through forcible subjugation. This often takes the form of intrusion. The political theory states that while other causes of war may be present, nationalism or spirit is almost always a factor. Associated with nationalism is the meridian, which is built on the idea that conquering other countries is glorious and brings honor and respect to the conqueror. Racism can also be linked to nationalism, as seen in Hitler's Germany. Adolf Halter went to war with Russia in part because the Russians were considered slaves, or a group of people the Nazis considered an inferior race. Historical examples of wars fought for nationalism are the Chichimeca War between 1550-1590 and World War I between 1914-1918.
A fifth cause of war is revenge, aimed at punishing to make amends or simply strike back for a perceived insult, which can often be a factor in the conduct of war. Revenge is also related to nationalism as the people of the wronged country are motivated to fight back with pride and spirit, unfortunately, this can lead to an endless chain of retaliatory wars that are very difficult to stop. Historically, revenge has been a factor in many European wars, such as World War II between 1939-1945 and the War on Terror.
The sixth cause of war is civil war. These generally take place when there is sharp internal disagreement within a country the disagreement can be about who rules, how the country should be run, or the people’s rights. These internal rifts often turn into chasms that result in violent conflict between two or more opposing groups. Civil wars can also be sparked by separatist groups who want to form their own independent country, or, as in the case of the American Civil War, states wanting to secede from a larger union. In world history, there have been several civil wars, namely: the American Civil War (1861-1861), the Russian Civil War (1917-1923), the Spanish Civil War (1936-1939), and the Korean War (1950-1953).
The seventh cause of war is revolutionary war. These occur when a large section of the population of the country revolts against the individuals or group that rules the country because they are dissatisfied with their leadership. Revolutions can begin for a variety of reasons, including economic hardship amongst certain sections of the population or perceived injustices committed by the ruling group. Other factors can contribute too such as unpopular wars with other countries revolutionary wars can easily descend into civil wars. Historical examples of revolutionary wars are the Portuguese Restoration War (1640-1668), the American Revolution (1775-1783), the French Revolution (1789-1799), and the Haitian Revolution (1791-18040).
And the last cause of war is defensive war. In today's world where military aggression is questioned, countries will often claim that they are fighting an aggressor or potential aggressor purely defensively and that their war is a ‘just’ war. These defensive wars can be particularly controversial when they are launched early, arguing essentially that ‘we attack them before they inevitably attack us’. A historical example of a defensive war is the Cold War between 1947-1991.
To summarize this essay, there are many reasons for wars, but the most recognized are economic gain, territorial conquest, religion, nationalism, revenge, civil war, revolutionary war, or defensive war.