Hi Simcha,

Great questions!

As for your first question, I think it is obvious that the Mishna does not mean that a war between brothers is a good idea or a Mitzvah. But unfortunately, as the Mishna brings from the Navi, it happened too many times in the past, and we can learn from these terrible experiences, that although there was a war, brothers still have mercy even in war circumstances, and they act differently than what might happen if a Jewish soldier falls into captivity by these enemies. A soldier in the Jewish army, might know more about the Jewish history and the way Ephraim treated Yehuda more than he might imagine how enemies can behave in war.

Regarding your second question, it is important to realize that this topic is widely spoken in the responsa literature. There were so many circumstances during the Galus that these questions came up. Is a Jew aloud to join the army if he knows he won't be able to keep Kosher? Is is widely agreed that there is a Heter of Dina de'Malchusa Dina, regarding the Issurim that the soldier might have to be involved (see Tshuvos Chasam Sofer 6, Likutim 29; Shu"t Mishne Halachos 9, 339).

The question of Retzicha and Yehareg ve'Al Yaavor is of course more serious, and was delt with during the first world war, and even British pilots who bombed in what was then Palestine, and might kill Jews on the ground.

There are a few answers regarding the problem of Yehareg ve'al Yaavor'. We must start with the Gemara Bava Metzia 83; b, where we find that Rebi Elazar Ben Rebi Shimon who was Moser Jewish thieves to the kingdom, and these were eventually killed. We see from here that there are circumstances that the laws of the government change the regular rules of Retzicha or Mesira. The Rishonim argue if Rebi Elazar is the Halacha, since there are a few Tanaim who thought him wrong. It seems from the Shu"t ha'Rashba (brought by the Bei Yosef, Yoreh Deah end of Siman 388) that even though it might be better to try not to do what Rebi Elazar did, it is Midas Chasidus but not an Issur, and people who deserve a death penalty according to the government, it is permitted to turn them in. The Ran and Mei'ri in Bava Metzia, seem to argue with the Rashba's opinion.

If a war is a legitimate decision of the government, we can say that according to the Rashba, the rule of Yehareg ve'Al Yaavor is not relevant. (See Haamek Davar, Bereishis 9;5).

Another aspect we need to think about, is if the rule of Yehareg ve'Al Yaavor apply in a case of Safek. Say, if a Jew is told, kill a Safek Jew or you will be killed, what is the Halaca? The Peri Megadim (brought in Hagahos Rebi Akiva Eiger, Yoreh Deah 157) as some other Achronim say that even in a Safek the rule applies. The Bach (in the same Siman) argues. This might help a bit in a case that if the soldier does not recruit, he will be killed.

Shu"t Avnei Shayish (1), says another big Chidush. He says that when Hatzalah of many others is involved in the dilemma, it might be permitted to join the army even if killing another Jew might be involved. He says that this is the Heter Ester ha'Malka used when she went willingly to Achashverosh. I f all Jews avoid recruiting to the army because of Safek of killing a Jew, this might change the outcome of the war.

Another aspect we find in some Achronim (see Chidushei Rebi Akiva Eiger, Kesubos 33; b) is an interesting discussion regarding the Halacha of Rodef. It is well known that if one sees someone who is intending to kill someone else, it is permitted to kill him since he is a Rodef. What if two people want to kill each other, is it permitted to kill either of them? Maybe both of them?

If we apply this discussion to our case, can the soldier killing his fellow Jew, consider him as a Rodef? This is a very difficult dilemma and the decision can be shuddering.

We must remember that we are dealing with very tragic cases and it is impossible to understand or judge cases where people were forced between two impossible options. When going through the material, we can see that the Rabbis dealing with these questions, came to the table with holy anxiety, and extreme caution. These cases were extremely traumatic and delt as such.

I hope this helps a bit,

Aharon Steiner