Many economic and political changes took place in Europe which promoted mutual distrust and the spirit of nationalism during the 19th and early 20th centuries. The following causes were responsible for the outbreak of the First World War.
Colonial Rivalries- The imperialist countries of Europe like Germany, France, Russia, Italy, England and Austria desired to acquire more and more colonies. Britain and France had already divided most of Africa and Asia. Germany and Italy had their own imperialist designs. Japan and the United States also rose as imperialist countries. The further conquest was possible only by dispossessing the imperialist countries already having a hold over the colonies. Hence a conflict was unavoidable.
Conflicts within Europe over the Balkan Issue- The six major European powers (Russia, Britain, Austria-Hungary, Germany, Italy and France) had their vested interests in the Balkan issue. The Balkan states had been under the control of Ottoman Turks for many centuries. When the Ottoman rule began to collapse in the 19th century the European powers longed to exploit the situation. The major claimants Russia and Austria-Hungary prepared themselves to wage a war and settle the issue by their armed strength.
Formation of Alliances- Germany, Austria and Italy formed the Triple Alliance in 1882. England, Russia and France formed the Triple Entente in 1907. Thus Europe was divided into two hostile groups. Hence their mutual rivalry resulted in a war.
Rivalry between Germany and France- Germany defeated France in 1870-71 in the Franco-Prussian war. Germany captured the important provinces of Alsace and Lorraine which were famous for iron deposits. Germany was not willing to return them. Hence the French people grew revengeful. Both France and Germany longed to capture Morocco in Africa. This further aggravated their mutual enmity. Hence the conflict became inevitable.
Enmity between Austria and Russia- Austria always opposed Serbia while Russia gave her full support. Austria annexed the provinces of Bosnia and Herzegovina but Serbia strongly opposed this move. This led to the Balkan wars. Hence Serbia’s approach to the Aegean sea became difficult. So Serbia became a staunch enemy of Austria. This enmity between Austria and Serbia and Russia corrupted the atmosphere.
Pan-Slav Movement- The Balkan countries had been under the rule of Ottoman Turks. However, in the nineteenth century, the Ottoman rule had begun to collapse. There were revolts by various nationalities for independence. The Russian Czars hoped that these areas would come under their control. Once the Ottomans were ousted from there. They encouraged a movement called the Pan-Slav movement which was based on the theory that all the Slavs of Eastern Europe were one people. Many areas in Austria-Hungary were also inhabited by the Slavs. Rusia, therefore, encouraged movements both against the Ottoman Empire and Austria-Hungary. The major Balkan country Serbia led the movement for uniting the areas inhabited by the Slavs in the Ottoman empire as well as in Austria-Hungary. Serbian nationalism was encouraged by Russia. Other major European powers were alarmed at the growth of Russain influences in the Balkans. They wanted to check the Russian influences while Austria-Hungary had plans of expansion in this area. Corresponding to the Pan-Slav Movement, there was a Pan-German Movement which aimed at the expansion of Germany all over Central Europe and in the Balkans. Italy claimed certain areas which were under Austrian rule. France hoped to recover not only Alsace-Lorraine which she had lost to Germany in 1871, but also to wreak vengeance on Germany for the humiliating defeat that she had suffered in the war with Germany in 1870-71.
Economic Exploitation of Backward Countries- The imperial powers competed to beat one another in exploiting the backward countries. This struggle led to war.
Lack of International Institution- At that time, there was no institution of international nature that could make efforts to avoid the possibility of war. All nations were free to do anything according to their selfish motives. The Hague conferences took some remarkable steps in this respect. Some important laws were made in these conferences to prevent war. But unfortunately, the conferences had no way or means by which European countries might be compelled to obey those laws. Owing to the lack of such effective means, these conferences failed in their mission. The countries did not hesitate to violate the laws made by these conferences. Every nation had a policy of its own. They did not care for the interests of other countries. In this way, the feeling of suspicion and disappointment was created everywhere in Europe.
The Murder of Prince Archduke of Austria- The Austrian Prince, Archduke Ferdinand was murdered by a Serbian in the Bosnian capital of Sarajevo on June 28, 1914 A.D. The situation in the world had already become very tense. The relations between Austria and Serbia were already strained. Though this murder was a minor incident yet it proved disastrous for world peace. Austria put the blame of the Archduke’s death on the Serbian Government and sent an ultimatum of war to her. At Russia’s instigation, the Serbian government refused to comply with the conditions of the ultimatum of war. Therefore Austria was compelled to declare war against Serbia on July 28, 1914. England and Germany failed in their attempts to make this war a local affair. Russia and France came to support Serbia. So Germany declared war on Russia and France. England wanted to keep aloof but she had to give her full support to Russia and France when Germany attacked Belgium. Thus Russia, England, France and Italy sided with Serbia and Germany and Turkey supported Austria. China, the United States and Japan too joined the war soon after. Hence this war culminated into the First World War.