How did world war ll happen and what was the impact?​

World War II was the deadliest military conflict in history in terms of total dead, with some 75 million people casualties including military and civilians, or around 3% of the world's population at the time. Many civilians died because of deliberate genocide, massacres, mass-bombings, disease, and starvation.

Explanation:

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    Hitler's invasion of Poland in September 1939 drove Great Britain and France to declare war on Germany, marking the beginning of World War II. Over the next six years, the conflict would take more lives and destroy more land and property around the globe than any previous war. In fact, World War II was the deadliest military conflict in history in terms of total dead, with some 75 million people casualties including military and civilians, or around 3% of the world's population at the time. Many civilians died because of deliberate genocide, massacres, mass-bombings, disease, and starvation.

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