Militarism, Alliance Systems, Imperialism, and Nationalism are often cited as the four main causes of World War I. Here are specific examples of how each of these factors contributed to the pre-war tensions:
Militarism:
Militarism refers to the glorification of military power and the belief that a country should maintain a strong military capability to protect its interests. In the years leading up to World War I, many European countries were engaged in a military arms race, with each country seeking to outdo the others in terms of military strength. For example, Germany's aggressive expansion of its navy and the building of dreadnought battleships led to tension and suspicion among other European powers, particularly Britain.
Alliance Systems:
In the years before World War I, countries formed alliances with one another for protection and security. The two main alliance systems were the Triple Entente (Britain, France, and Russia) and the Triple Alliance (Germany, Austria-Hungary, and Italy). These alliances created a dangerous situation in which a small conflict between two countries could quickly escalate into a larger war, as each country felt obligated to defend its allies. For example, when Austria-Hungary declared war on Serbia in 1914, Russia felt obligated to defend Serbia due to their alliance, which then led Germany to declare war on Russia.
Imperialism:
Imperialism refers to a policy of extending a country's power and influence through colonization, use of military force, or other means. In the years before World War I, many European countries were engaged in imperialistic practices, particularly in Africa and Asia. The competition for colonies and resources often led to conflict between European powers. For example, the Moroccan Crisis of 1905-1906 was caused by Germany's challenge to France's dominance in Morocco, which nearly led to war.
Nationalism:
Nationalism refers to a strong sense of pride and loyalty to one's country. In the years before World War I, nationalism was a powerful force in Europe, with many countries asserting their independence and seeking to expand their territory. Nationalist movements often led to tension and conflict between countries, as each country sought to protect its national interests. For example, the assassination of Archduke Franz Ferdinand of Austria-Hungary in 1914 by a Serbian nationalist led to the outbreak of World War I.