The collapse of the Soviet system offered the third-largest Jewish population in the world the oportunity to worship freely for the first time in seven decades. More than 1 million Soviet Jews left for Israel and the United States, leaving at least 2 million to rebuild the ruins of Jewish community life with generous support from the Diaspora. Veterans of the Underground who remained, Jewish leaders who emerged after the fall of Communism and dozens of rabbis sent by Chabad-Lubavitch began building a new infrastructure of synagogues, community centers and day schools throughout the vast territory stretching through ten time zones. The latent embers kept alive by the Jewish underground movement burst into flames to restore literally hundreds of Jewish communities. In November 1998, leaders of these dispersed communities recognized the need for a united and efficient umbrella group. They pooled their professional, financial and technical resources to create the Federation of Jewish Communities.