Causes of World War II in the context of "Demilitarized zone"

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.

Auschwitz (German: [ˈaʊ̯ʃvɪts]), also known as Oświęcim (Polish: [ɔˈɕfjɛɲ.t͡ɕim]), was a complex of over 40 concentration and extermination camps operated by Nazi Germany in occupied Poland (in a portion annexed into Germany in 1939) during World War II and the Holocaust. It consisted of Auschwitz I, the main camp (Stammlager) in Oświęcim; Auschwitz II-Birkenau, a concentration and extermination camp with gas chambers, Auschwitz III-Monowitz, a labour camp for the chemical conglomerate IG Farben, and dozens of subcamps. The camps became a major site of the Nazis' Final Solution to the Jewish question.

After Germany initiated World War II by invading Poland in September 1939, the Schutzstaffel (SS) converted Auschwitz I, an army barracks, into a prisoner-of-war camp. The initial transport of political detainees to Auschwitz consisted almost solely of Poles (for whom the camp was initially established). For the first two years, the majority of inmates were Polish. In May 1940, German criminals brought to the camp as functionaries established the camp's reputation for sadism. Prisoners were beaten, tortured, and executed for the most trivial of reasons. The first gassings—of Soviet and Polish prisoners—took place in block 11 of Auschwitz I around August 1941.

Pan-Germanism (German: Pangermanismus or Alldeutsche Bewegung), also occasionally known as Pan-Germanicism, is a pan-nationalist political idea. Pan-Germanism seeks to unify all ethnic Germans, German-speaking people, and possibly also non-German Germanic peoples – into a single nation-state known as Greater Germany.

Pan-Germanism was highly influential in German politics in the 19th century during the unification of Germany when the German Empire was proclaimed as a nation-state in 1871 but without Germanophone Switzerland, Austria-Hungary, Luxembourg and Liechtenstein (Kleindeutsche Lösung/Lesser Germany) and the first half of the 20th century in Austria-Hungary and the German Empire. From the late 19th century, many Pan-Germanist thinkers, since 1891 organized in the Pan-German League, had adopted openly ethnocentric and racist ideologies, and ultimately gave rise to the foreign policy Heim ins Reich pursued by Nazi Germany under Adolf Hitler from 1938, one of the primary factors leading to the outbreak of World War II. The concept of a Greater Germany was attempted to be put into practice as the Greater Germanic Reich (German: Großgermanisches Reich), fully styled the Greater Germanic Reich of the German Nation (German: Großgermanisches Reich der Deutschen Nation). As a result of the Second World War, there was a clear backlash against Pan-Germanism and other related ideologies. Today, pan-Germanism is mainly limited to a few nationalist groups, mainly on the political right in Germany and Austria.

World War II or the Second World War (1 September 1939 – 2 September 1945) was a global conflict between the Allied powers 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.