NISSAN (Katznelson), AVRAHAM (1888–1956), labor politician in Palestine and Israel diplomat, brother of Reuben *Katznelson. Born in Bobruisk, Belorussia, he was a medical officer in the Russian army during World War I. In 1917, between the two revolutions, he headed the Organization of Jewish Soldiers in the Russian army on the Caucasus front (10,000 men) and was attracted to Joseph *Trumpeldor's plan to set up Jewish battalions of 200,000 soldiers and volunteers and transport them to the front in Palestine to fight together with the British army for the liberation of Ereẓ Israel from the Turks. In 1919–20 he was the head of the Palestine Office of the Zionist Executive in Constantinople. In 1921–23 Nissan was active at the central office of Hitaḥdut (the union of *Ha-Po'el ha-Ẓa'ir and *Ẓe'irei Zion) in Vienna and Berlin. He settled in Palestine in 1924, served as the director of the health department of the Zionist Executive and as a member of the Va'ad Le'ummi (1931–48). He was also a member of the central committee of the Ha-Po'el ha-Ẓa'ir Party and of Mapai. From 1950 until his death, he was Israel's minister to the Scandinavian countries in Stockholm.