Operation Barbarossa

Operation Barbarossa was the massive military invasion of the Soviet Union by Nazi Germany and its European Axis allies. It began on June 22, 1941, during World War II. This operation was the largest and costliest military offensive in human history. It opened the Eastern Front, which became the largest and deadliest land war ever fought. The invasion also brought the Soviet Union into the Allied powers.

The invasion was driven by specific ideological and material goals. Nazi Germany wanted to secure "living space" for the German people to thrive. They targeted agricultural lands in Ukraine and Byelorussia for food. They also sought mineral resources and oil fields in the Caucasus. To achieve this, they planned to control territory up to the A–A line. This line ran between Arkhangelsk and Astrakhan.

Nazi leaders implemented a racial policy known as Generalplan Ost. This plan aimed to reorganize Eastern Europe through ethnic cleansing. It planned the removal of native Slavic peoples through mass deportation to Siberia. The goal was to replace them with Germans through a process called Germanisation. This included enslavement and genocide to create a "Thousand-Year Reich." Paramilitary death squads, known as the SS, also carried out mass shootings and gassing operations. These actions murdered over one million Soviet Jews as part of the Holocaust.

Before the fighting began, Germany and the Soviet Union had a strategic agreement. In August 1939, they signed the Molotov–Ribbentrop Pact. This was a non-aggression pact meant to prevent conflict. It included a secret protocol to divide Eastern European border states. However, Nazi Germany broke this pact by launching the invasion. Soviet leader Joseph Stalin received intelligence about the coming attack. He chose not to order a mobilization of the Red Army. He feared that preparing for war might provoke Germany. This left Soviet forces caught unprepared and poorly positioned.

The military operation involved three main German groups. Army Group North moved through the Baltic lands. They began a siege of Leningrad on September 8, 1941. This siege lasted until 1944. Army Group Centre was the strongest group. They captured Smolensk in late July 1941. They then began a drive toward Moscow in October. Army Group South invaded from occupied Poland. They captured Kiev on September 19, 1941. They also took Kharkov and Rostov-on-Don later that year.

The scale of the conflict was immense. More than 3.8 million Axis troops invaded along the front. Around 10 million combatants took part in the opening phase. The operation resulted in over 8 million casualties by December 5, 1941. The Axis forces captured five million Soviet Red Army troops. They also killed or starved 3.3 million prisoners of war. Millions of civilians were also killed during the invasion.

By late 1941, the German offensive began to stall. Army Group Centre reached the outskirts of Moscow by October 2. However, they faced severe logistical problems with supplies. The terrain became very muddy, which slowed their movement. The soldiers were not equipped for the brutal Russian winter. At the same time, they faced determined Soviet resistance. On December 5, 1941, the Soviets launched a major counteroffensive. This failure reversed the fortunes of Nazi Germany. It led to a war of attrition that Germany could not sustain.