This is a two-part series exploring ideological currents within and in response to the early 20th c. Zionist movement. Part 1 focuses on the historical context and emergent non-Zionist, anti-Zionist, and divergent Zionist ideas and ideologies that spread among the Jewish populations of Eastern and Central Europe between the world wars. Part 2 will focus on a select group of thinkers representing a range of perspectives on and in opposition to Zionism.