Operation Barbarossa in the context of "Einsatzgruppen"

World War II or the Second World War (1 September 1939 – 2 September 1945) was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were put on trial for war crimes.

The causes of World War II included unresolved tensions in the aftermath of World War I, the rise of fascism in Europe and militarism in Japan. Key events preceding the war included Japan's invasion of Manchuria in 1931, the Spanish Civil War, the outbreak of the Second Sino-Japanese War in 1937, and Germany's annexations of Austria and the Sudetenland. World War II is generally considered to have begun on 1 September 1939, when Nazi Germany, under Adolf Hitler, invaded Poland, after which the United Kingdom and France declared war on Germany. Poland was divided between Germany and the Soviet Union under the Molotov–Ribbentrop Pact. In 1940, the Soviet Union annexed the Baltic states and parts of Finland and Romania. After the fall of France in June 1940, the war continued mainly between Germany, now assisted by Fascist Italy, and the British Empire, with fighting in the Balkans, Mediterranean, and Middle East, the aerial Battle of Britain and the Blitz, and the naval Battle of the Atlantic. Through campaigns and treaties, Germany gained control of much of continental Europe and formed the Axis alliance with Italy, Japan, and other countries. In June 1941, Germany invaded the Soviet Union, opening the Eastern Front and initially making large territorial gains.

The Baltic states—Estonia, Latvia and Lithuania—were occupied and annexed by the Soviet Union in 1940 and remained under its control until its dissolution in 1991. For a period of several years during World War II, Nazi Germany occupied the Baltic states after it invaded the Soviet Union in 1941.

The initial Soviet invasion and occupation of the Baltic states began in June 1940 under the Molotov–Ribbentrop Pact, made between the Soviet Union and Nazi Germany in August 1939, before the outbreak of World War II. The three independent Baltic countries were annexed as constituent Republics of the Soviet Union in August 1940. Most Western countries did not recognise this annexation, and considered it illegal. In July 1941, the occupation of the Baltic states by Nazi Germany took place, just weeks after its invasion of the Soviet Union. The Third Reich incorporated them into its Reichskommissariat Ostland. In 1944, the Soviet Union recaptured most of the Baltic states as a result of the Red Army's Baltic Offensive, trapping the remaining German forces in the Courland Pocket until their formal surrender in May 1945.

The Eastern Front, also known as the Great Patriotic War in the Soviet Union and its successor states, and the German–Soviet War in modern Germany and Ukraine, was a theatre of World War II fought between the European Axis powers and Allies, including the Soviet Union (USSR) and Poland. It encompassed Central Europe, Eastern Europe, Northeast Europe (Baltics), and Southeast Europe (Balkans), and lasted from 22 June 1941 to 9 May 1945. Of the estimated 70–85 million deaths attributed to the war, around 30 million occurred on the Eastern Front, including 9 million children. The Eastern Front was decisive in determining the outcome in the European theatre of operations in World War II and is the main cause of the defeat of Nazi Germany and the Axis nations. Historian Geoffrey Roberts noted that "more than 80 percent of all combat during the Second World War took place on the Eastern Front".

The Axis forces, led by Germany, invaded the Soviet Union in Operation Barbarossa on 22 June 1941. Despite warnings and the deployment of Axis armies on his borders, Stalin refused to believe that Hitler would invade and forbade any defensive preparations. Thus the Soviets were caught completely unprepared. They were unable to halt deep Axis advances into Russia, which came close to seizing Moscow. However, the Axis failed to capture the city, and Hitler shifted his focus to the oil fields of the Caucasus the following year. German forces advanced into the Caucasus under Fall Blau ("Case Blue"), launched on 28 June 1942. The Soviets decisively defeated the Axis at the Battle of Stalingrad—the bloodiest battle in the war and arguably in all of history—making it one of the key turning points of the front. A second great Axis defeat, at the Battle of Kursk, crippled German offensive capabilities permanently and cleared the way for Soviet offensives. Several Axis allies defected to the Allies, such as Italy, Romania and Bulgaria. The Eastern Front concluded with the capture of Berlin, followed by the signing of the German Instrument of Surrender on 8 May, ending the Eastern Front and the war in Europe.

Smolensk is a city and the administrative center of Smolensk Oblast, Russia, located on the Dnieper River, 360 kilometers (220 mi) west-southwest of Moscow. It has a population of 316,570 (2021 census).

First mentioned in 863, it is one of the oldest cities in Russia. It has been a regional capital for most of the past millennium, beginning as the capital of the Principality of Smolensk in the 11th-15th centuries, then the Smolensk Voivodeship of Lithuania and the Polish–Lithuanian Commonwealth, and Smolensk Governorate and Oblast within Russia. It was the main stronghold of the Smolensk Gate, a geostrategically significant pass between the Daugava and Dnieper rivers, and as such was an important point of contention in the struggle for dominance in Eastern Europe, passing at various times between Lithuania, Poland and Russia. In more recent history, it was the site of two battles in 1812 and 1941 during the French invasion of Russia and Operation Barbarossa respectively on their paths towards Moscow. It was the place of the Smolensk air disaster of 2010.

Totalitarianism is a political system and a form of government that prohibits opposition from political parties, disregards and outlaws the political claims of individual and group opposition to the state, and completely controls the public sphere and the private sphere of society. In the field of political science, totalitarianism is the extreme form of authoritarianism, wherein all political power is held by a dictator. This figure controls the national politics and peoples of the nation with continual propaganda campaigns that are broadcast by state-controlled and state-aligned private mass communications media.

The totalitarian government uses ideology to control most aspects of human life, such as the political economy of the country, the system of education, the arts, sciences, and private morality of its citizens. In the exercise of power, the difference between a totalitarian regime of government and an authoritarian regime of government is one of degree; whereas totalitarianism features a charismatic dictator and a fixed worldview, authoritarianism only features a dictator who holds power for the sake of holding power. The authoritarian dictator is supported, either jointly or individually, by a military junta and by the socio-economic elites who are the ruling class of the country.

The third presidential term of Franklin D. Roosevelt began on January 20, 1941, when he was once again inaugurated as the 32nd president of the United States, and the fourth term of his presidency ended with his death on April 12, 1945. Roosevelt won a third term by defeating Republican nominee Wendell Willkie in the 1940 presidential election. He remains the only president to serve for more than two terms. Unlike his first two terms, Roosevelt's third and fourth terms were dominated by foreign policy concerns, as the United States became involved in World War II in December 1941.

Roosevelt won congressional approval of the Lend-Lease program, which was designed to aid the United Kingdom in its war against Nazi Germany, while the U.S. remained officially neutral. After Germany began war against the Soviet Union in June 1941, Roosevelt extended Lend-Lease to the Soviet Union as well. In Asia, Roosevelt provided aid to the Republic of China, which was resisting an invasion by the Empire of Japan. In response to the July 1941 Japanese occupation of French Indochina, Roosevelt expanded a trade embargo to cut off oil that Japan urgently needed for its fleet. When Roosevelt refused to end the embargo, on December 7, 1941, Japan launched an attack on the U.S. fleet stationed at Pearl Harbor in Hawaii. Isolationist sentiment in the U.S. immediately collapsed and Congress declared war on Japan. After Germany declared war on the U.S., Congress declared war on Germany and Italy. To win the war, the U.S., Britain and the Soviet Union assembled a large coalition of the Allies. The U.S. funded much of the war efforts of the other allies, and supplied munitions, food, and oil. In consultation with his Army and Navy and British Prime Minister Winston Churchill, Roosevelt decided on a Europe first strategy, which focused on defeating Germany before Japan. In practice, however, in 1942 and 1943 the U.S. focused on fighting Japan.

The Crimean campaign was conducted by the Axis as part of Operation Barbarossa during World War II. The invading force was led by Germany with support from Romania and Italy, while the Soviet Union took up defensive positions throughout the Crimean Peninsula. The Axis offensive routed the Red Army and enabled the three-year-long German occupation of Crimea.

Beginning on 26 September 1941, the German 11th Army and the Romanian Third Army and Fourth Army were involved in the fighting. They were opposed by the Soviet 51st Army and elements of the Black Sea Fleet. After the campaign, Crimea was occupied by Germany's Army Group A, with the 17th Army as a major subordinate formation.

The Reichskommissariat Ukraine (RKU; lit. 'Reich Commissariat of Ukraine') was an administrative entity of the Reich Ministry for the Occupied Eastern Territories of Nazi Germany from 1941 to 1944. It served as the German civilian occupation regime in the Ukrainian SSR and parts of the Byelorussian SSR, Russian SFSR, and eastern Poland during the Eastern Front of World War II.

Reichskommissariat Ukraine was established after the early success of the Wehrmacht's Operation Barbarossa for territory under the military administration of Army Group South Rear Area. The German civil administration was based in Rovno (Rivne) with Erich Koch serving as the only Reichskommissar during its existence.