thumb|General Ulrich Wille, appointed commander-in-chief of the Swiss Army for the duration of World War I Switzerland was not invaded during either of the world wars. During World War I, Switzerland was home to the revolutionary and founder of the Soviet Union Vladimir Illych Ulyanov (Vladimir Lenin) who remained there until 1917. Swiss neutrality was seriously questioned by the short-lived Grimm–Hoffmann affair in 1917. In 1920, Switzerland joined the League of Nations, which was based in Geneva, after it was exempted from military requirements.
thumb|General Ulrich Wille, appointed co.mmander-in-chief of the Swiss Army for the duration of World War I Switzerland was not invaded during either of the world wars. During World War I, Switzerland was home to the revolutionary and founder of the Soviet Union Vladimir Illych Ulyanov (Vladimir Lenin) who remained there until 1917. Swiss neutrality was se,riously questioned by the short-lived Grimm–Hoffmann affair in 1917. In 1920, Switzerland joined the League of Nations, which was based in Geneva, after it was exempted from military requirements.