<P> The Treaty of Portsmouth formally ended the 1904--05 Russo - Japanese War . It was signed on September 5, 1905 after negotiations lasting from August 6 to August 30, at the Portsmouth Naval Shipyard in Kittery, Maine, United States . U.S. President Theodore Roosevelt was instrumental in the negotiations, and won the Nobel Peace Prize for his efforts . </P> <P> The war of 1904--05 was fought between the Empire of Russia, an international power with one of the largest armies in the world, and the Empire of Japan, a nation which had only recently industrialized after two - and - a-half centuries of isolation . A series of battles in the Liaodong Peninsula had resulted in Russian armies being driven from southern Manchuria, and the Battle of Tsushima had resulted in a cataclysm for the Imperial Russian Navy . The war was unpopular with the Russian public, and the Russian government was under increasing threat of revolution at home . On the other hand, the Japanese economy was severely strained by the war, with rapidly mounting foreign debts, and its forces in Manchuria faced the problem of ever - extending supply lines . No Russian territory had been seized, and the Russians continued to build up reinforcements via the Trans - Siberian Railway . Recognizing that a long - term war was not to Japan's advantage, as early as July 1904 the Japanese government had begun seeking out intermediaries to assist in bringing the war to a negotiated conclusion . </P> <P> The intermediary approached by the Japanese side was the United States President Theodore Roosevelt, who had publicly expressed a pro-Japanese stance at the beginning of the war . However, as the war progressed, Roosevelt had begun to show concerns on the strengthening military power of Japan and its impact on long - term United States interests in Asia . In February 1905, Roosevelt sent messages to the Russian government via the US ambassador to St Petersburg . Initially, the Russians were unresponsive, with Tsar Nicholas II still adamant that Russia would prove victorious in time . At this point, the Japanese government was also lukewarm to a peace treaty, as Japanese armies were enjoying an unbroken string of victories . However, after the Battle of Mukden, which was extremely costly to both sides in terms of manpower and resources, Japanese Foreign Minister Komura Jutarō judged that the time was now critical for Japan to push for a settlement . </P> <P> On March 8, 1905, Japanese Army Minister Terauchi Masatake met with the American minister to Japan, Lloyd Griscom, to convey word to Roosevelt that Japan was ready to negotiate . However, from the Russian side, a positive response did not come until after the loss of the Russian fleet at the Battle of Tsushima . Two days after the battle, Tsar Nicholas II met with his grand dukes and military leadership and agreed to discuss peace . On June 7, 1905, Roosevelt met with Kaneko Kentarō, a Japanese diplomat, and on June 8 received a positive reply from Russia . Roosevelt chose Portsmouth, New Hampshire, as the site for the negotiations, primarily because the talks were to begin in August, and the cooler climate in Portsmouth would avoid subjecting the parties to the sweltering Washington, D.C. summer . </P>

Who won the nobel peace prize for his efforts to end the vietnam war