How did the alliance system contribute to the start of world war 1?

Throughout the nineteenth century, the major European powers made a great effort to maintain the balance of power throughout Europe, resulting in a complex network of political and military alliances across the continent for the early twentieth century. can be traced back to 1815, with the formation of the Holy Alliance between Prussia, Austria and Russia, was in October 1873, with the negotiation of the League of Three Emperors, when it began to forge the system of alliances launched during the Big war. Conceived by the German Chancellor, Otto von Bismarck, the League of Three Emperors promised to be an alliance between the monarchies of Austria-Hungary, Russia and Germany, although it ultimately failed due to the lack of agreement between Austria-Hungary and Russia on the policy continue in the Balkans. This led to the formation of the Double Alliance between Austria-Hungary and Germany in 1879, seen as a way to contain Russian influence in the Balkans, where the Ottoman Empire continued to weaken.In 1882, Italy joined the alliance, what became the Triple Alliance.

Throughout his administration, Bismarck had worked to keep Russia on the German side, in an effort to avoid a war on two fronts, against France and Russia. Despite this, when William II came to the throne and became a Kaiser, his differences with Bismarck forced the latter to retreat and his system of alliances was progressively dismantled, including the Treaty of reinsurance with Russia, which the emperor refused to accept. renewed in 1890. Thus, only two years later the Franco-Russian Alliance was created to counteract the Triple Alliance. France wanted the revenge after the defeat suffered against Prussia in the Franco-Prussian War of 1870-1871. While Paris was besieged, the German princes had proclaimed the Empire (the so-called Second Reich) in the palace of Versailles, which meant an offense to the French. The Third Republic lost Alsace and Lorraine, which became part of the new German Reich. His recovery was coveted by the French president, Raymond Poincaré, from Lorraine.In general, the French generations of the late nineteenth century and, above all, the military estates, grew up with the nationalist idea of ​​avenging the affront by recovering those territories. As an example of the airs that were breathed in France in 1914, only 1.5% of the recruits of the French Army resisted the mobilization, in comparison with 30% of 1870. Although maintaining the distances with respect to their potential allies , United Kingdom feared more and more the German military and naval expansion, reason why in 1904 signed a series of agreements with France, known like the Entente Cordiale and three years later signed the Anglo-Russian Entente (1907). While these agreements did not represent a formal alliance between the British Empire, France and Russia, and in practice were primarily an arrangement with respect to colonial issues, they gave rise to the possibility that Britain could enter on behalf of France or Russia. future conflicts, so this system of bilateral agreements became known as the Triple Entente.

answer:

it caused mass african migration, african populations to grow, african empires to topple, and racism against slaves to emerge.