Yōsuke Matsuoka was a Japanese diplomat and Minister of Foreign Affairs of the Empire of Japan during the early stages of World War II. He is best known for his defiant speech at the League of Nations in February 1933, ending Japan's participation in the organization. He was also one of the architects of the Tripartite Pact and the Soviet–Japanese Neutrality Pact in the years immediately prior to the outbreak of war.

The Soviet–Japanese Neutrality Pact , also known as the Japanese–Soviet Non-aggression Pact , was a non-aggression pact between the Soviet Union and the Empire of Japan signed on April 13, 1941, two years after the conclusion of the Soviet-Japanese Border War. The agreement meant that for most of World War II, the two nations fought against each other's allies but not against each other. In 1945, late in the war, the Soviets scrapped the pact and joined the Allied campaign against Japan.