The White Paper was a major concession to the Arabs. For the Jews of Palestine, it was an abandonment of British support for a Jewish national homeland promised in the Balfour Declaration, at a time when the situation for Jews in Europe was growing more perilous. Within weeks, Jewish paramilitary squads were attacking British forces, planting explosives in Jerusalem's central post office, and carrying out attacks on civilians in Arab souks. The White Paper, it was clear, had shaken Jewish-British relations in Palestine.