The alliance system ideated by the German chancellor Otto von Bismarck kept peace in Europe but its main aim was, however, to forestall the possibility that, in the event of war, Germany would have to fight it on two fronts (basically France and Russia). This was achieved by diplomatically isolating France so that its dream of recapturing its lost provinces of Alsace-Lorraine couldn't be fulfilled. This was done by, firstly, the creation of the League of the Three Emperors or Dreikaiserbund. It was first projected as a meeting of the monarchs of Germany, Austria-Hungary and Russia in 1872 and confirmed the following year, the 22nd of October 1873. Here, the very general and formless agreement was given a more solid form by military agreements promising to help any country attacked by a fourth party. And all this even though that there was mutual rivalry between Russia and Austria-Hungary in the Balkans. This proved to be a concrete way to isolate France for as E. Eyck mentions, "the League ensured that neither Austria-Hungary nor Russia was available as an ally for France". At this point, Bismarck didn't consider Britain as a potential French ally as they had a long history of rivalry. Secondly, in 1887 the Reinsurance Treaty was signed with Russia in which it promised to support Russia's claims to the strait and to remain neutral in the event of war unless it attacked Austria-Hungary, the same with Russia, who promised to remain neutral unless it attacked France.
When Bismarck was dismissed the Kaiser and his advisers were convinced that the most likely wars in Europe would be Germany against France or Russia against Austria-Hungary so this, together to the thought that the Reinsurance treaty was not compatible with Germany's promises to Austria-Hungary in 1879, led to the treaty not to be renewed in 1890 and the Russo-German friendship came to an end. The following year, the Triple Alliance between Germany, France and Italy was renewed. This alliance originated as the Dual Alliance in 1879 between Germany and Austria Hungary when Germany had a dispute with Russia so to get protection against an eventual Russian attack both countries promised to help each other if any of them was attacked. Three years later, in 1882 Italy joined the Dual Alliance.
The breakage of the Russo-German relationship in 1890 together with the renewal of the Triple Alliance caused fear in both France and Russia. So in 1892 France and Russia formed the Franco-Russian alliance. The two fronts were now starting to become concrete and the coalition Bismarck tried so meticulously to avoid was formed.
We can see that disintegration of the Bismarck system led to a series of events that formed the two main fronts that would combat in the Great War the following century, the Dual (afterwards Triple) Alliance and Franco-Russian alliance that later evolved into the Triple Entente. E. Eyck argues that the Bismarck...