In the three weeks following the breaking of the Pact, the Soviet Union attempted to defend itself against vast German advances; in the process, the Soviet Union suffered 750,000 casualties, and lost 10,000 tanks and 4,000 aircraft.[167] Within six months, the Soviet military had suffered 4.3 million casualties[168] and the Germans had captured three million Soviet prisoners, two million of which would die in German captivity by February 1942.[167] German forces had advanced 1,050 miles (1,690 kilometers), and maintained a linearly-measured front of 1,900 miles (3,058 kilometers).[169]