Realizing that its national resources had reached the limit and, hence, it could not continue with the war any longer, Japan, which had been keeping the advantageous position all through the Russo-Japanese War, requested the U.S.A., which had at that time comparable power to the great world powers, the U.K. and France, and was eager to enhance its international status, to mediate the negotiation between them.
日露戦争において終始優勢を保っていた日本は、これ以上の戦争継続が国力の面で限界であったことから、当時英仏列強に肩を並べるまでに成長し国際的権威を高めようとしていた米国に仲介を依頼し交渉を行った。