What was a major effect of the Russo-Japanese War?

Japan defeated Russia in the Russo-Japanese War of 1904–1905, strengthening Japan’s position in East Asia. The Treaty of Portsmouth recognized Japan’s interests in Korea and gave it influence in parts of Manchuria, so the best answer is “Japan gained influence in nations such as Manchuria and Korea.” Japan did not annex all of Manchuria, and Russia was the defeated side.

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