אֵין הַמֶּלֶךְ נִלְחָם תְּחִלָּה אֶלָּא מִלְחֶמֶת מִצְוָה.
וְאֵי זוֹ הִיא מִלְחֶמֶת מִצְוָה?
זוֹ מִלְחֶמֶת שִׁבְעָה עֲמָמִים. וּמִלְחֶמֶת עֲמָלֵק.
וְעֶזְרַת יִשְׂרָאֵל מִיַּד צָר שֶׁבָּא עֲלֵיהֶם.
A priori, the king does not go to fight other than a War of Mitzvoh (Mandatory War). What is a War of Mitzvoh? This is the war against the Seven Nations30 or the war against Amalek or any war to assuage Israel of a persecutor. (Rambam Melachim 5)
Here Rambam speaks of a King and how he handles the two types of war. But what about times when there is no king?
What kind of Jewish government is needed for the obligatory/defensive war (Milchemet Chova) to be officially and Halachicly "Milchemet Mitzvah"?
- Does it have to be a kingdom with a Jewish king? (for example, Yehoshua (and till Saul) wasn't anointed officially as a king)
- Can it be under a cooperative government (aka the State of Israel's democracy)
- Can it be under Gentile government (as in the Purim story), or if this C"V would happen in today's France against the Jews?