In 1923, the Rebbe met Rabbi Yosef Yitzchak Schneersohn, who then served as "Rebbe" (teacher and leader) of the world wide Chabad-Lubavitch movement.
Six years earlier, the Communist Party had wrested control of the Russian Empire, and the Party's Yevsekzia ("Jewish Section") embarked on a ruthless war against Judaism. Schools, synagogues and religious institutions were shut down. Religious leaders were imprisoned, and many were summarily shot in the underground execution chambers of the Secret Police.
Rabbi Yosef Yitzchak led the struggle to keep Judaism alive in Soviet Russia, dispatching his emissaries to the length and breadth of the land to establish underground schools, mikvahs, and supply lines of financial aid and kosher food. The Rebbe joined him in the highly secret and highly dangerous work. In 1926, the Rebbe became engaged to marry Rabbi Yosef Yitzchak's second daughter, Chaya Mushka.
When, in the summer of 1927, agents of the Yevsekzia paid a midnight visit to Rabbi Yosef Yitzchak's Leningrad apartment to arrest him, Rebbetzin Chaya Mushka signaled the fact to the Rebbe from a window, so that the Rebbe could destroy the "evidence", warn all those involved, and set in motion the international effort that would commute the death sentence placed on Rabbi Yosef Yitzchak and obtain his release.
The Rebbe was one of the select circle of family members allowed to leave the country with Rabbi Yosef Yitzchak in 1927. The network of teachers and activists remained in place, and Rabbi Yosef Yitzchak continued to direct its activities from the other side of the Iron Curtain until his passing in 1950, when the Rebbe, whose own involvement never abated, assumed the leadership of Chabad.
In the darkest years of anti-religious persecution, the Rebbe maintained contact with the Jews of the Soviet Union through many secret channels, even sending emissaries in the guise of tourists and business travelers. With the collapse of Communism in the beginning of this decade, the Rebbe's network simply moved aboveground, to continue to provide material and spiritual aid to Russian Jewry in light of day.
Today, there are Chabad-Lubavich emissaries in the former Soviet Union, laboring in 84 cities help Russia's Jews to reclaim their heritage.
Whenever he spoke about the suffering of Soviet Jewry and the tremendous sacrifices they made to cling to their faith, the Rebbe would be overcome by emotion. Whatever we do for them, he would often say, is but an infinitesimal part of what they give to us with their valiant commitment to our shared destiny.