A report on the persecutions of Jews in Russia presented at the 15th Zionist Congress which took place in Basel, Switzerland in 1927. The prosperity in Palestine was followed by a severe economic crisis and unemployment, which affected nearly 8,000 workers. Hunger and poverty drove many from the country and aliyah dwindled. Preoccupation with "breaking the crisis" at the 15th Congress, held in Basle on Aug. 30–Sept. 11, 1927, spoiled the celebrations in honor of the 30th anniversary of the First Congress. Weizmann outlined a proposal for overcoming the crisis, and Ruppin delivered one of his brilliant Congress speeches on pioneering and its meaning for Zionism. The Executive elected did not include a labor representative and its most forceful personality was Harry Sacher. Eulogies on Ahad Ha-Am were delivered by Martin Buber and Nahum Sokolow.

Hitahadut was a Socialist-Zionist party formed in 1920 by the union of the Palestine Workers' Party, Ha-Po'el ha-Za'ir, with a majority of the Ze'irei Zion groups in the Diaspora. Ze'irei Zion groups had been formed in Russia at the beginning of the 20th century by young Zionists who espoused the views of Ha-Po'el ha-Za'ir and intended to join that party upon their settlement in Erez Israel. The program of Ze'irei Zion, announced at its second congress in Petrograd in 1917, postulated the necessity to establish a Jewish labor commonwealth in the Land of Israel and redirect the Jewish masses in the Diaspora to productive occupations.

Hitahadut, which was represented at the World Zionist Organization and its various bodies, devoted its energies primarily to fostering the He-Halutz (pioneering) movement in the Diaspora and stimulating immigration to Palestine. It functioned very effectively in both these spheres during the 1920s. It was also able to create an active pioneering movement in Soviet Russia, with a membership of thousands, despite the persecution of Zionism by the Soviet regime. In its Diaspora-oriented activities Hitahadut devoted its attention primarily to cultivating economically productive labor. The movement had representatives in the parliaments of several countries (Poland, Lithuania, Latvia, and Rumania), in municipal councils, and in the governing bodies of Jewish communities. Unlike other Jewish socialist groups which supported Yiddish, Hitahadut championed the revival of Hebrew. It was one of the prime movers of the Tarbut movement in Eastern Europe, and much of the teaching and administrative personnel of the Hebrew schools came from its ranks. Hitahadut also supported the founding of a special pioneering youth movement that crystallized in the late 1920s under the name Gordonia. Hitahadut and Po'alei Zion usually appeared conjointly at Zionist Congresses, and when Ha-Po'el ha-Za'ir and Ahdut ha-Avodah in Palestine merged to form the Mifleget Po'alei Erez Yisrael (Mapai, 1930), the former two groups also amalgamated in 1932 at their world conference in Danzig, and formed the Ihud Olami.