During WWI, an exchange of letters was going on between the Sharif Hussein of Mecca and Sir Henry McMahon, who was British High Commissioner in Egypt. Letters were concerning the future political status of the Arab lands under the Turkish Empire. The Arab side was already planning a revolt against the Ottoman Empire and all British did was encourage revolt which caused a disruption to the Ottoman Empire which was a German ally in the WWI.
In November 1917 the Balfour Declaration of 1917 was issued. The declaration was a letter from the Foreign Secretary, Lord Balfour to Lord Rothschild, head of the British Zionist movement and it stated:
“His Majesty’s Government view with favour the establishment in Palestine of a national home for Jewish people, and will use their best endeavours to facilitate the achievement of this object, it being clearly understood that nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine, or the rights and political status enjoyed by Jews in any other country.”
On 24th July 1922, in London, the terms of the British Mandate over Palestine was approved by the Council of the League of Nations. The objective of the League of Nations Mandate system was to look after the parts of old Turkish Empire which was destroyed during WWI. However the mandate ignored the political rights of the Arabs which were promised in the letters exchanged between Hussein and McMahon during WWI. The leadership of Arabs pressed the British to give them political freedom. They mostly did it by reminding British about their promises during WWI.
During the Mandate, the Jewish community in Palestine grew incredibly from one-sixth to almost one-third of the population. This was caused by the immigration of the Jews into the Palestine, according to official records 367,845 Jews immigrated legally between 1920 and 1945. Although it was estimated that another 50-60,000 Jews immigrated illegally during the WWI. Such a high immigration of Jews caused a little opposition from the Palestinian Arabs but as anti-Semitism grew in Europe during late 19th and early 20th centuries, Jewish immigration to Palestine increased.
The MacDonald report restricted Jewish immigration to Palestine in 1939. This decision was very controversial, especially in the latter years of British rule. The policy was disliked by both Arabs and Jews as they both had different reasons to it.
WWII and the Holocaust started shortly after the British limitation, Jews running away from Nazis were placed in detention camps or deported to places like Mauritius. In 1939 Zionists organized an illegal immigration that rescued many thousands of the European Jews from Nazis by shipping them to Palestine. Some of the boats which carried illegal immigrants were caught and returned back. The last immigration boat was hit by a torpedo, the ship sank causing nearly 800 people to die. Soon after the WWII illegal immigration resumed and many Jews had used it to get to Palestine.
After this numerous Arab attacks took place on the Jewish community, in response Jews formed the Haganah, a Jewish paramilitary organization, was formed on 15th June 1920 to defend Jewish residents. Later on the Haganah had changed into the Irgun. Irgun was a military group established by Zionists that operated in Palestine between 1931 and 1948. It was an armed expression of the Zionist ideology. The Irgun has been sabotaging strategic places like electricity facilities, radio and telephone lines. At some stage they started to publicize some of its plans and its goals by organizing street announcements, newspapers and some underground radio stations. The British answer was arresting of few Irgun members (some of them were tortured to get extra information about Irgun).
The continued violence in Palestine had caused Britain to ask the United Nations to solve the problem and them the United Nations Special Committee on Palestine (UNSCOP) was set up. Finally on August 31st UNSCOP released its report and making the United Nations Partition Plan for Palestine (Resolution 181). The resolution was approved by a vote. However many people believe that the countries which were voting were influenced by the US government, this happened because most of the important people at this time in USA were Jews and they influenced the US government. Them the government promised money that many countries needed after WWII for voting FOR the partition.