Unlike the situation in Central or Western Europe, where challenges to Jewish beliefs and institutions usually led to religious and theological reform, in Eastern Europe (as well as among the Sephardim, for the most part), Jews tended to chose between traditional religion and a broad spectrum of secular expressions of Judaism. The result was that the influence of non-Orthodox Jewish religious movements was marginal.
In the early 20th century, Aguddat Israel ("the Israelite union") was established as the political arm of traditional Orthodoxy, representing a wide range of anti-modern branches who were not ready to accept the cultural openness of Hirsch's Neo-Orthodoxy.
The Aguddat Israel had its beginnings at a conference that took place in 1912 at Kattowitz. The Tenth World Zionist Congress had recently defeated a resolution proposed by the Mizrachi religious Zionist faction requesting equal support for religious schools. As a result several prominent Mizrachi supporters had withdrawn from the Zionist movement and allied themselves with the forces that would constitute the Aguddat Israel. During the First World War the centre of the movement shifted from Russia to Frankfort, Germany.
Active in the Aguddah were several Hasidic groups, alongside advocates of Lithuanian-style yeshivahs, and even a Labor wing that called for the establishment of strictly religious agricultural settlements in Palestine, outside the framework of the Zionist movement.
The Aguddat Israel wielded considerable political power, sending representatives to the Polish parliament.
While they were largely hostile to Zionism as a movement, arguing that the Jews constituted a religious community defined by Torah and not a normal nation, the establishment of the State of Israel in 1948 makes that antagonism largely irrelevant. In Israel they have represented the interests of the "ultra-Orthodox" constituency in the national parliament, the Knesset. Owing to the nature of Israel's proportional representation system, the relatively small numbers of Aguddat Israel representatives has often been crucial to the survival of government coalitions, and hence they have very effective in channeling resources towards their yeshivahs and other institutions. They have advocated religious legislation; e.g., public observance of Sabbath and dietary laws, the rejection of non-Orthodox conversions in the definition of "Jew" in Israel's "Law of Return".
Policy decisions of Aguddat Israel must be ratified by their "Council of Torah Scholars," which consists of leading rabbis from the main constituent groups. When participating in government coalitions, they have generally refrained from accepting actual cabinet posts.
Aguddat Israel does not have clear positions on issues related to security or foreign policy. Since they do not attach eschatological or religious significance to the State of Israel, they generally approach such questions pragmatically.
The Aguddat Israel established a broad assortment of religious institutions in Europe, including the "Beis Yakov" girl's schools and programmes for "adult education." Most of these institutions have been transplanted to Israel and America. In Israel they have maintained their separate school system (Hinnukh 'Atzma'i) outside the state-run Religious School System.
Sources: Prof. Eliezer Siegel's Home Page