During World War I, the conditions for the Jews in the Ottoman Empire worsened. All those Jews who were of an enemy nationality were exiled and others were drafted into the Ottoman army. Many of those exiled fled to Egypt and the United States. Those who remained in the Ottoman ruled Palestine faced hard economic times. There was disagreement whether to support the British or the Turks. A clandestine group, Nili, was established to pass information to the British in the hope of defeating the Ottomans and ending their rule over Palestine. The purpose and members of the Nili were discovered. All involved were executed by the Ottomans except its founder, Aaron Aaronsohn, who escaped to Egypt. During World War I, the Jewish population in Palestine diminished by a third due to deportations, immigration, economic trouble and disease. During World War I, there were two British battalions of Jews, called the Zion Mule Corps, who were to fight on the front of Palestine. They helped in the British capture of Ottoman Syria (including Palestine), leading to the Turkish surrender. The members of the Zion Mule Corps later made up the Yishuv's defence groups that would fight against the British.