According to Zionist theology, there should be a chiyuv for every Jewish man worldwide to join the army of their respective host countries; after all, surely there are defensive reasons for at least some of the worldwide areas of operation even if the Zionists have foolishly put themselves in a far worse position than that of other countries.
LiOlam al yiftach adam peh laSatan, so I’ll use a hypothetical case. Say there were millions (the number doesn’t matter) of Jews living in Haiti and Haiti were under threat from the Dominican Republic. Why would there be a substantive pikuach nefesh difference between defending Haiti and defending Israel? There are both Jews and non-Jews in both.
The answer is, of course, that the goal of Zionist wars are not for pikuach nefesh purposes but rather they are for the secular Nationalist value that Rav Herschel Schechter and others hold. This value something like: the “lium” or nation needs the State for its national existence and this State, itself, is worthy of pikuach nefesh, having nothing to do with its citizens.
I find it farcical that you’re actually considering Zionist wars to be michemes mitzvah when they are really milchemes shmad, regardless of the fact that they are like the arsonists who then come running with the fire truck after setting the conflagration.