How does one explain the fact that so many gedolei Yisroel were opposed to Zionism and the State of Israel? In particular the Chazon Ish, the Brisker Rav, the Satmar Rebbe. There have always been differences of opinion in Judaism, but here we have major leading rabbis who literally declared Zionism to be heresy.
In general, religious people, especially rabbis, are wary of new ideas. Rav Kook had to go out of his way to stress that Zionism isn’t a “reform’, but to the contrary, is a return (!) to the original (!) Judaism of Eretz Yisrael, as clearly seen in the Tanach, where the nation of Israel is meant to live in the Jewish Land, in a Jewish state, serve in the Jewish army, speaks the Holy Language, works for a living, etc. Rav Yissachar Teichtel, one of the greatest poskim in Hungary, was a strong anti-Zionist before the Holocaust. He writes in his introduction to Eim HaBanim Smeicha, that he had fiercely opposed it simply because he saw his rabbis did so, especially as a secular movement. He confesses that most rabbis, including himself, spent all their time on Talmud and practical halacha, and not on theoretical philosophy, aggadita (often skipped in yeshiva learning) or current events, which are inherently open to many alternative approaches. Only when he had to go into hiding, was forced to evaluate the practical and pragmatic actions demanded by the times, and had time to think through the issue, did he totally overhaul his opinion and became a religious-Zionist. He writes that although he had known all of the sources which he quotes by-heart (!) beforehand, only now did he really put them together systematically (p. 21)! Similarly, Rav Yitchak Elchanan Spector, generally accepted as the leading posek of his era, was a staunch supporter of the Zionist movement, but nevertheless, his own brash secretary, R. Ya’akov Lifshutz, dared think that “he knows better than his own rebbe” and even forged letters against Zionism! In short, we are not talking about an opposition based upon sources, but rather based upon conservatism, wariness of new ideas, and of cooperating with secular Jews. Many other rabbis, at least as great as those you mentioned, like R. Spector, the Netziv, Avnei Nezer, Ohr Same’ach, and Rav Kook, actively supported Zionism, and surely wouldn’t be called heretics by anyone!! After the Holocaust, the Chazon Ish himself cooperated with the Israeli authorities. Only the Satmar rebbe, who is militantly controversial regarding many issues, called even religious Zionists: heretics and even gentiles, and in the words of Rav Yitzchak Hutner, “Rav Kook was 20 times greater than all those who opposed him combined” (heard personally by the eye-witness R. Eliezer Waldman, rosh yeshivat Kiryat Arba).