The article examines the role of Turkey in Nazi Germany’s strategic calculations during Operation Barbarossa in 1941. Positioned at the crossroads of Europe, Asia, and the Middle East, Turkey’s geopolitical significance was defined by its control of the Bosporus and Dardanelles straits and its proximity to vital oil regions in the Caucasus, Iraq, and Iran. Berlin sought to integrate Turkey into the anti-Soviet coalition or at least secure its friendly neutrality, which would ease pressure on the Wehrmacht’s southern flank and limit British influence in the region. Drawing on German diplomatic records, Turkish archival materials, memoirs, and contemporary research, the article analyzes diplomatic negotiations, propaganda, and intelligence operations aimed at Ankara, as well as the Turkish leadership’s response to the outbreak of the German-Soviet war. Particular attention is paid to the German-Turkish Treaty of Friendship signed on June 18, 1941, and the unrealized “Gertrude” plan. The findings suggest that Turkey’s policy of cautious neutrality, orchestrated by President İsmet İnönü, prevented Germany from exploiting Turkish resources and territory, while simultaneously allowing Ankara to strengthen its international standing and safeguard national sovereignty. Thus, Turkey functioned as a “non-activated reserve” in Hitler’s strategy, illustrating the limits of German diplomacy in the context of World War II.