The Reinsurance Treaty was a diplomatic agreement between the German Empire and the Russian Empire that was in effect from 1887 to 1890. Only a handful of top officials in Berlin and St. Petersburg knew of its existence since it was so secret. The treaty played a critical role in German Chancellor Otto von Bismarck's extremely complex and ingenious network of alliances and agreements, which aimed to keep the peace in Europe and to maintain Germany's economic, diplomatic and political dominance. It helped keep the peace for both Russia and Germany.
The treaty provided that both parties would remain neutral if the other became involved in a war with a third great power, but that would not apply if Germany attacked France or if Russia attacked Austria-Hungary. Germany paid for Russian friendship by agreeing that Bulgaria and Eastern Rumelia (now part of southern Bulgaria) were in the Russian sphere of influence and by agreeing to support Russian action to keep the Black Sea as its own preserve. After Bismarck had lost power in 1890, his enemies in the Foreign Ministry convinced the Kaiser that the treaty was too much in Russia's favor and should not be renewed. The cancellation, as had been like the treaty itself, remained a total secret. Russia, however, wanted the protections that the treaty had afforded, and so was angered by its termination. Needing new allies, Russia opened negotiations with Germany's enemy, France. The resulting Franco-Russian Alliance of 1891–1892 to 1917 rapidly began to take shape. Historians consider the new alliance a major disaster for Germany and one of the long-term causes of the First World War.
Background
The Reinsurance Treaty originated after the German-Austrian-Russian Dreikaiserbund (League of the Three Emperors) had lapsed in 1887 because of competition between Austria-Hungary and the Russian Empire for spheres of influence in the Balkans. In early 1887, a Russian diplomat went to Berlin to propose a treaty in which Russia would be a friendly neutral country during a war between Germany and France, and in return, Germany would recognise Russian dominance in Bulgaria and promise a friendly neutrality if Russia seized the Turkish Straits from the Ottoman Empire. Bismarck strongly supported the idea, but Alexander III rejected the plan until Foreign Minister Nikolay Girs convinced him that it would be best for Russia in the absence of French friendship. Bismarck refused Russia's request for Germany to stay neutral if Russia went to war against Austria and explained that Berlin had an ironclad Triple Alliance with Vienna.
Bismarck had a long-term policy of preserving the peace in Europe, which was threatened by the growing competition between Russia and Austria–Hungary for dominance over the Balkans. He felt that an agreement with Russia was essential to prevent a Russian alliance with France, and he always had the policy of keeping France isolated diplomatically to avoid Germany from fighting a two-front war against both France and Russia. Bismarck risked the expansion of the Russian sphere of influence toward the Mediterranean and diplomatic tensions with Vienna.
The treaty signed by Bismarck and Russian Foreign Minister Nikolay Girs had two parts: Germany and Russia agreed to observe benevolent neutrality if either become involved in a war with a third country. If Germany attacked France or if Russia attacked Austria-Hungary, that provision would not apply. In those cases, the distinguished bilateral alliances could come into effect. The Reinsurance Treaty applied only if France or Austria–Hungary were the aggressors. In the most secret completion protocol, Germany would declare neutrality if Russia intervened against the Ottoman control of the Bosphorus and the Dardanelles.
Nonrenewal
As part of Bismarck's system of "periphery diversion", the treaty was highly dependent on his prestige. After Kaiser Wilhelm II had removed Bismarck from office in 1890, Russia asked for a renewal of the treaty, but Germany refused. Bismarck's successor, Leo von Caprivi, felt no need to mollify Russia. German foreign policy establishment was unanimous in rejecting a renewal because the treaty contradicted so many other German positions with regard to Austria-Hungry, the United Kingdom, Romania and Italy. For example, the Reinsurance Treaty contradicted the secret Austro-Romanian Treaty of 1883, in which Germany and Austria-Hungary promised to protect Romania; Russia knew nothing of that treaty.