well he vetoed it even though the majority of countries involved were down with the racial equality clause that the japanese presented. here's something you could have found on your own, but I am nice so I found it for you:
Reaction
In the end he felt that British support for the League of Nations was a more crucial goal. The Japanese media fully covered the progress of the conference, leading to an alienation of Japanese public opinion towards the United States of America, leading to broader conflicts later on. In the United States, racial riots occurred by the American deliberate inaction.[13]
As such, this point could be listed among the many causes of conflict which lead to World War II, which were left unaddressed at the close of World War I. The rejection of the racial equality clause provoked important factor in turning Japan away from cooperation with the West and toward nationalistic policies.[14] In 1923, Anglo-Japanese Alliance was ended. Then Japan and Italy established closer relationship to Germany. On the other hand, Japan made a decision of prohibiting the expulsion of the Jews in Japan, Manchuria, and China in accordance with the spirit of the racial equality[15][16] and advocated a political slogan Hakko Ichiu.
It is both ironic, and indicative of the scale of the later changes in the mood of the international system, that this contentious point of racial equality would later be incorporated into the United Nations Charter in 1945 as the fundamental principle of international justice. Civil Rights Act was enforced in 1964.Apartheid was abolished in 1994.
