What alliance was bismarcks greatest fear?

Bismarck's greatest fear was the formation of a strong alliance between France and Russia, which he believed could encircle Germany and threaten its security. He sought to isolate France diplomatically while maintaining good relations with Russia through treaties, such as the Three Emperors' League and the Reinsurance Treaty. This diplomatic strategy aimed to prevent a two-front war and maintain a balance of power in Europe. Ultimately, Bismarck's fears were realized after his dismissal, leading to the Franco-Russian Alliance and increased tensions in Europe.