Mostly, after WWI, Britain promised them their current stretch of land in the Middle East. While Britain did not deliver, this did give them their claims, and their holdings were secured in WWII and further legitimized in the current war on terror.
Creation of the State of Israel. Following the defeat of the Ottoman Empire in World War I, the British assumed control of Palestine. In November 1917, the British government issued the Balfour Declaration, announcing its intention to facilitate the "establishment in Palestine of a national home for the Jewish people."
