Operation Rübezahl  Operation Rübezahl was the beginning of a strategic retreat by Nazi German troops from Serbia after the front change of Romania and Bulgaria during World War II. In summer 1944, German soldiers were doing sweeps against Yugoslavian partisans led by communist Josip Broz Tito. But on 30 August, after Kingdom of Romania and Bulgaria split from their Nazi ally, Germany entered into a crisis on the Balkan front. While the forces of the National Liberation Army were moving to unite with the Soviet Red Army in Serbia, German troops tried to avoid defeat in that strategic area by implementing "Operation Rübezahl" to enable the organised retreat of Germans from Serbia. Among them there were:   Between 20-22 August, German troops surrounded and destroyed a particularly huge partisan unit moving westwards from Croatia to Serbia. Only a few partisans survived thanks to Allied planes which managed to land on battered airstrips, air-lifting about a thousand injured to hospitals located in Italy.