By mid-August 1944, most of northwestern France was under Allied control, and from there, the Allied advance moved rapidly. Hitler ordered the evacuation of southern France, and German troops also began the process of evacuating Paris itself. At almost the same time, Soviet troops invading from the other front first crossed Germany’s eastern border.
Even as it became inevitable that France would fall to the Allies, however, the Nazi war machine continued deporting French Jews to Auschwitz and other extermination camps without letup. A few days later, on August 25, Allied forces entered Paris, by which point all remaining German troops had either evacuated or been taken prisoner.
Even though the war in Europe would continue for another seven months, September 1944 brought Germany perilously close to defeat. During that month, Allied troops overran most of France, pushed deep into Belgium, and were on the verge of entering the Netherlands. The first Allied soldier crossed into Germany on September 10; although this mission was only a brief excursion, Allied ground missions into Germany would become increasingly frequent.
After the success of Operation Overlord, the Allies had the ability to launch bomber raids from France, Italy, and Britain, which vastly expanded the range and duration of aerial attacks inside Germany. Simultaneously, the Soviets were closing in from the east: although Warsaw was still under German control, the Red Army had taken much of eastern Poland. The Soviets also had advanced into Czechoslovakia, Romania, Bulgaria, and Yugoslavia—the latter two of which even signed formal agreements of cooperation with the USSR.
By the autumn of 1944, Germany was surrounded on all sides. Allied air strikes on German industrial facilities, particularly oil reserves, prevented the Luftwaffe from posing the serious threat that it once had. This gap in Germany’s defense left the country very vulnerable to attack. Moreover, the fuel situation in Germany was becoming truly desperate, especially after the city of Ploiesti, Romania, fell to the Red Army on August 30. Ploiesti had been the last oil source available to Germany, as it was now cut off from the Black Sea.
Few in the German high command could have failed to recognize that they were in serious trouble, even if they could not admit it publicly. A resistance movement against Hitler grew among the German officer corps, and several attempts were made on Hitler’s life throughout the summer, including a bombing on July 20 that nearly succeeded. After the failed attempt, Hitler cracked down mercilessly on known opponents, executing more than 4,000 of them.