ShalomNewYork.com

“Q: How was it possible to establish the State of Israel when the Gemara (Ketubot 111a) says that it is forbidden to rebel against the nations of the world?
A: While the Gemara in Ketubot does mention the prohibition of rebelling against the nations of the world, it is not found in the law codes – not in the Rambam or the Shulchan Aruch. There are two possibilities why this is so: 1. It is a dispute and we did not hold this way (Our Rabbi, Ha-Rav Tzvi Yehudah, Le-Netivot Yisrael, vol. 2, p. 217). 2. This is not a legal (halachic) issue but a homilectic (aggadic issue) (see Shut Avnei Nezer, Yoreh Deah #454 and Ha-Rav Menachem Kasher’s “Ha-Tekufah Ha-Gedolah,” p. 187).
There is a commentary to the Rambam’s Sefer Ha-Mitzvot called “Megillat Ester” by Ha-Rav Yitzchak Leon and he did in fact write that it is forbidden to conquer Eretz Yisrael since it is it is forbidden to rebel against the nations of the world. He argued with the Ramban who said that it is a mitzvah to conquer the Land of Israel throughout all generations (Additions to the Sefer Ha-Mitzvot, positive mitzvah #4). It is thus a dispute between the Ramban and the author of “Megillat Ester.” According to the general rules of deciding Halachah, we must follow one of them. The Ramban is well-known to all and there are many of his rulings in the Shulchan Aruch, while there is not even one law from the “Megillat Esther.” Furthermore, the Rambam did not cite the Gemara that it is forbidden to rebel against the nations of the world. ” more@RavAviner.com