“Take vengeance for Bnai Yisrael against the Midianites and afterward you will be gathered to your people.”(BeMidbar 31:2)
Maimonides does not include within his list of the 613 mitzvot an obligation to possess or live in the land of Israel. However, Maimonides does maintain that we are obligated to possess and live in the land of Israel. His exclusion of this obligation from his list of the 613 mitzvot is based on technical considerations and does not reflect a disregard for the centrality of the land of Israel within the Torah.
However, Maimonides’ position regarding the land of Israel does present a problem. In order to understand this problem, an introduction is needed. The Torah urges us to always pursue peace. Nonetheless, the Torah recognizes that sometimes the Jewish nation must engage in war. Even in war, the laws and ethics of the Torah cannot be disregarded. The Torah mandates various laws for the conduct of war. In general, the Torah outlines two categories of war – milchemet mitzvah and milchemet reshut. Milchemet mitzvah is a war which is a mitzvah. Milchemet reshut is a war which is not a mitzvah. It is optional.
Obviously, these terms need some clarification. Under what circumstances is a war regarded as a mitzvah? Maimonides does not include in his codification of the mitzvot a specific mitzvah to wage war. Instead, Maimonides records two mitzvot regarding specific wars – war to destroy Amalek and war to destroy the seven nations of Cana’an. This indicates that according to Maimonides, a milchemet mitzvah is a war authorized by some specific obligation in the Torah. In other words, a war waged to destroy Amalek is a milchemet mitzvah because it fulfills the mitzvah to destroy Amalek. A war against the seven nations is a milchemet mitzvah because it fulfills the mitzvah to destroy the seven nations. Maimonides adds that milchemet mitzvah includes a third case. A war to rescue the nation from an attacking adversary is also regarded as a milchemet mitzvah. Although, there is some controversy regarding the identity of the specific mitzvah that is fulfilled in this last case, it is reasonable to assume that we are obligated to defend our fellow Jew. Therefore, a war waged to defend and save other Jews meets the criterion for being defined as a milchemet mitzvah. In contrast, a war which is not required by a specific Torah obligation is not a milchemet mitzvah. It is a milchemet reshut.
There are various differences between a milchemet mitzvah and a milchemet reshut. For example, all members of Bnai Yisrael are obligated to participate in a milchemet mitzvah. However, there are various exemptions for a milchemet reshut. Because a milchemet mitzvah is waged in response to a Torah obligation, no further authorization is required for this war to be waged. However, because a milchemet reshut is not waged in response to a specific Torah obligation, it must be authorized by Bait Din – the court.
As explained above, Maimonides agrees that we are obligated by the Torah to possess the land of Israel and to live in the land. Therefore, we would expect that a war waged in order to seize control of the land would be a milchemet mitzvah. However, as indicated above, Maimonides only identifies three forms of milchemet mitzvah – a war to destroy Amalek, a war to destroy the seven nations of Cana’an, and a war to save other Jews. He does not include in this list a war waged in order to take possession of the land of Israel. Yet, it would seem that such a conflict would meet Maimonides’ criterion for a milchemet mitzvah.
In order to answer this question, we must return to an issue mentioned earlier. According to Maimonides, a war waged in order to save members of Bnai Yisrael is a milchemet mitzvah. It is reasonable to regard such a war as obligatory. However, as mentioned earlier, there is some controversy regarding the exact identity of the mitzvah that obligates such conduct. Let us consider this issue more closely.
In the above passage, Moshe is instructed to wage war against Midyan. This was fulfills a commandment outlined in last week’s parasha. There, Hashem reminds Moshe that Midyan had attempted to destroy Bnai Yisrael. Therefore, Bnai Yisrael must eliminate Midyan. In our parasha, Hashem tells Moshe that the time has come to fulfill this obligation. The midrash comments that one is permitted to take another’s life in order to defend oneself. In other words, if a person is aware that another individual is preparing to attach him, he may take the measures needed to save himself. He may even take the life of this person that plans to assail him. The midrash explains that this law is derived from Hashem’s instructions to Moshe regarding Midyan. Midyan had proven through previous behavior that it was determined to destroy Bnai Yisrael. In instructing Moshe to annihilate Midyan, Hashem specifically noted Midyan’s previous attempts to destroy Bnai Yisrael. The midrash asserts that the message of the Torah is clear. If one plans to kill you, you may protect yourself by killing this would-be assailant before he can attack you.
This midrash would seem to contradict a well-known teaching of our Sages. The Torah informs us that if we discover a burglar in our home, we are permitted to kill him. The Sages explain that this is an act of self-defense. It is assumed that if the homeowner opposes the burglar, the thief is prepared to kill his opponent. Therefore, the homeowner’s actions against the burglar are regarded as self-defense. Rashi suggests that this law is the source for the dictum that one is permitted to kill someone in order to defend oneself. In other words, it is agreed that one may kill another person as a preemptive measure to save oneself. However, the source for this law is disputed. The midrash suggests that the source is Hashem’s instructions to Moshe to destroy Midyan. Rashi seems to disagree with the midrash and suggest an alternative source. According to Rashi, the source is the law permitting the homeowner to kill a burglar.
Rav Aharon Soloveitchik suggests that there is not contradiction between Rashi and the midrash. Rashi is identifying the source for an individual’s right to take preemptive measures against an attacker. However, the midrash is extending this rule to the nation. In other words, the midrash is explaining that just as the individual is permitted and encouraged to defend himself and preempt an attack, so too the nation of Bnai Yisrael is authorized and expected to take the same action.
Rav Aharon explains that this midrash is the source for Maimonides’ ruling that a war waged to save fellow Jews is a milchemet mitzvah. Even if one is not under personal attack, the midrash rules that we are obligated to take preemptive action on a national level. In other words, the midrash extends to the nation as a whole the right of the homeowner to protect himself.
Rav Aharon further explains that his thesis has important implications. According to his explanation of Maimonides, the obligation of the nation to defend itself is an extension of the prerogative of the homeowner. He notes that the homeowner may exercise this prerogative in order to protect his property. In other words, the homeowner is not expected to step aside and allow the thief to rob him. He is permitted and encouraged to oppose the robber. Rav Aharon points out that if the thief succeeded in ejecting the homeowner from his property, the homeowner would not be deprived of his prerogative. He would have every right to forcibly reclaim his property even at the expense of the thief’s life.
Rav Aharon suggests that the same reasoning applies to the national prerogative or obligation to defend itself. This obligation includes the right and obligation to protect its property – the land of Israel – from all those who seek to steal it. Furthermore, if we are removed from the land, we have the right to reclaim it – just as the homeowner may reclaim his property. In short, according to Rav Aharon, the obligation of the Jewish nation to defend itself implies a right and obligation to defend the land of Israel.
Based on this reasoning, Rav Aharon answers our question on Maimonides. Why does Maimonides not include within his list of conflicts that are milchemet mitzvah a war waged to possess the land of Israel. Rav Aharon answers that Maimonides does include this war in his list. This war is regarded as a war of self-defense. Just as the homeowner is regarded as acting is self-defense when he protects his property, so too Bnai Yisrael is acting in its own self-defense when it protects its land from those who would take it from the Jewish people.  Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Melachim 5:9-12. Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Melachim 5:1.  Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Melachim 7:4.  Rabbaynu Moshe ben Maimon (Rambam / Maimonides) Mishne Torah, Hilchot Melachim 5:2.  Sefer BeMidbar 25:17-18.  Midrash Tanchuma, Parshat Pinchas, Chapter 3.  Sefer Shemot 22:1.  Rabbaynu Shlomo ben Yitzchak (Rashi), Commentary on Sefer Shemot 22:1.  Rav Aharon Soloveitchik, Settling the Land of Israel and Milchemet Mitzvah in Current Times, Or HaMizrach, October 2003.