1)Was the Hakamas HaMedinah a violation of the Shalosh Shevuos?
It is a little hard to deal with the complex matter of the Three Oaths and the State of Israel in this limited forum. I will try to set down the basics of the issue.
Commenting on three verses found in the Song of Songs, all of which mention an oath imposed upon the daughters of Jerusalem to the effect that they may not awaken or arouse the love, until it is desired, the Talmud quotes the following teaching: Rabbi Yosi in the name of Rabbi Hanina taught: What are these three oaths? One that Israel shall not ascend [to Eretz Yisrael] the wall [by force]; one that the God adjured Israel not to rebel against the nations of the world; and one that God adjured the nations of the world not to oppress Israel overmuch (Kesubos 111a).
The first two Oaths convey similar messages: Israel is forbidden to throw off the yoke of the nations, and is likewise forbidden to use force to make an ascent to the Holy Land.
Do the Oaths apply to the establishment of the State of Israel? In Va-Yoel Moshe, Rabbi Yoel Teitelbaum (the Satmar Rebbe) answers this with an emphatic yes. Indeed, even Rabbi Zvi Hirsch Kalischer (d. 1875), who in the mid-nineteenth century advocated immigration en mass to the Holy Land (and whose vigorous campaign in favor of the settlement was instrumental in laying the foundations for modern Zionism), was wary of violating the Oaths by employing force or political means to establish a Jewish government. The entire vision (in his outlook) of settling the Land was limited to peaceful means, with the consent of nations.
Although many halachic authorities mention the Oaths, several approaches are suggested in limiting their application, and which serve as a halachic defense for the initial establishment of the State of Israel.
1. Rabbi Chayim Vital, the great disciple of Rabbi Yitzchak Luria, writes that the Oaths expired after the termination of the first millennium of the two thousand years of Messiah.
2. In discussing the Oaths, the Vilna Gaon makes specific mention of going out to rebuild the Temple. This could be construed as implying that the prohibition of re-settling the Land by force is limited to the building of the Temple—a position that would explain the political activism of the Gaon’s disciples who immigrated to the Holy Land.
3. Rabbi Zvi Hirsch Kalischer writes that the Oaths only prohibit forcing the actual End, a destiny whose achievement must remain solely in the hands of God. Concerning the beginning, the path of settling the Land that leads “little by little” towards the End, there is no prohibition (and in his opinion, doing so is a religious obligation).
4. Rabbi Aviezer of Tiktin (one of the disciples of the Vilna Gaon who immigrated to the Holy Land in the beginning of of the nineteenth century) writes that the prohibitions do not apply to “extraordinary times” in which the coming of Mashiach may be hastened by human action.
5. Rabbi Yisrael of Shklov (a leading disciple of the Vilna Gaon and one of the leaders of the original settlers) contended that because the Gentiles had not kept their part of the Oaths [namely: not to persecute the Jewish People “overly”], the Jews were absolved of theirs.
6. With regard to the oath not to “ascend the wall,” Rabbi Yehudah Alkalai (d. 1878) explained that the injunction prohibits only collective ascending in a sudden, revolutionary thrust; according to him, the Oath is actually supportive of the move towards settling the Land of Israel: Israel is adjured not to “ascend the wall,” but is obligated to ascend!
In spite of these possibilities, many have written that the establishment of the State was an infringement of the Oaths. It should be noted that once Jews are living on the Land of Israel, there is certainly no halachic question involved in defending against enemies (the Oaths refer specifically to ascending), and therefore the current legitimacy of the I.D.F. is not an issue.
Sources: Vayoel Moshe (pp. 92-93); The Writings of Rabbi Kalischer (Jerusalem, 1947), p. 230; Introduction to Shaar Hakdamot; Annotations of Vilna Gaon to Tikkun 26, p. 70a, cited in Siddur Hagra (Jerusalem, 1971), p. 48; Shaarei Tzedek (Jerusalem, 1843), p. 46b; Kitvei Harav Yehudah Alkalai, ed. Yitzchak Werfel (Jerusalem, 1944), pp. 202, 240, 302.
[I have written in greater detail on this topic in a forthcoming book entitled Prophecies and Providence.]