In short, it supported Zionism and the idea of a Jewish homeland. Arthur Balfour was the man who supported this idea, and it was rooted in anti-Semitism. While anti-Semitism is most commonly associated with Nazi Germany, plenty of countries in the western world harbored vast hostility towards the Jewish population. The Balfour Declaration is an example of this. The purpose was not to give the Jews a homeland out of kindness, rather it was an attempt to get rid of Jew out of Europe.