Given that the Balfour Declaration was not a unilateral document on behalf of the British but rather something which had been agreed upon privately by allied diplomats before it was issued, it is viewed as the beginning of a legal process, which involved the San Remo conference of 1920 where the Declaration was officially adopted by the allied powers and latter, the creation of the British Mandate for Palestine in 1922.

The implementation of the Declaration was not without its failings. It provided for the safeguarding of the rights of the residents of Palestine saying 'nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine'. In the run up to WWII that the British wanted to placate the Arab leadership in the Mandate. They issued a White Paper limiting Jewish immigration to the Mandate to fifteen thousand every year for five years, ultimately refusing entry to thousands of Jewish refugees from Europe, many of whom would tragically die in the Holocaust. [Wikipedia]