Answer:
Japan was viewed as the most powerful nation in East Asia.
The Treaty of Portsmouth was signed.
Japan's influence in Korea increased.
Step-by-step explanation:
The Russo-Japanese War which was fought between the empires of Russia and Japan over their common imperial interests of attaining Korea and Manchuria. This war, fought between 1904- 1905, started at the moment right after the proposed negotiations for Korea failed, which led Japan to lead a surprise attack on the Russian army at its base Port Arthur in China.
With this war, Japan stakes its claim as being the most powerful nation in the East Asian area. With the refusal of Tsar Nicholas II to back away and retreat, the war went on until the United States intervened. This was documented by the Treaty of Portsmouth which was signed in September 5, 1905, under the mediation of President Theodore Roosevelt. The complete victory of the Japanese army led to the increase of its influence in the Korean Peninsula.