What was the Reinsurance Treaty between Germany and Russia in 1887?

The Reinsurance Treaty of 1887 was an agreement between Germany and Russia, aimed at maintaining neutrality if either country became involved in a war with a third power. It was designed to counterbalance the Franco-Russian Alliance and to prevent a two-front war for Germany. The treaty was a continuation of Bismarck's diplomatic strategy to isolate France and stabilize relations with Russia. However, it was not renewed after Bismarck's dismissal in 1890, leading to increased tensions in Europe.