HaRav Shlomo Aviner is Head of Yeshivat Ateret Yerushalayim.
Question: Is it permitted for three male soldiers and one female soldier - who is a driver or paramedic - to remain together in a Hummer (Humvee) military transport vehicle or does it transgress the issue of yichud (the prohibition of being alone with a woman who isn’t one’s wife)?
Answer: Certainly it is forbidden. Not specifically on account of the law of yichud, because Ashkenazim permit yichud of one woman with three men, whereas Sephardim forbid it (Shulchan Aruch, Even Ha-Ezer 22:5). One could even argue that in pressing circumstances even Sephardim could be lenient.
But - all this is not relevant to the matter, because when “גס לבו“ his heart is crude," the matter is forbidden (Beit Shmuel there §13). “His heart is crude" does not mean that he speaks coarsely, but that they are accustomed to one another - they are acquaintances, they are friends.
And the prohibition here is not only about yichud, but that one must distance himself very, very much from women other than one's wife, as is written by the Rambam (Hilchot Issurei Bi’ah, ch. 21; Shulchan Aruch, Even Ha-Ezer §21; Kitzur Shulchan Aruch 152:8). It is also forbidden to gaze at another woman, forbidden to engage in excessive conversation, forbidden to laugh together, etc., which cannot be avoided when remaining together for eight hours.
The matter is similar to the parable of the Sages about the father who bought his son a perfume shop on the street of brothels. When the father caught him engaged in sin with women in the brothels, he became angry with him. A Sage said to him: What did you think would happen?
Of course, in our case the female soldier is not, Heaven forbid, a wanton woman, and the soldiers are not in such a state, but one cannot expect with certainty that they will not sin, because of natural impulses.
An IDF researcher has already written that there is “licentiousness" in this, and certainly this is not the intention of the authorities in the IDF, but unfortunately this is the result.
Therefore this phenomenon must be stopped completely, and it is forbidden for soldiers to be in such a situation. They must request not to be placed together with women, and if they are not listened to, they must say that this is against the regulations of joint service. And if they are compelled - they must refuse, even if they are sent to prison.
And if this situation becomes permanent, it must be ruled that soldiers should not enlist at all in these units. There are already religious soldiers who do not enlist in artillery or in combat intelligence collection for this reason, and it may be that also not in the armored corps.
“And your camp shall be holy, for the Lord your God walks in the midst of your camp" (based on Deuteronomy 23:15), and the Lord does not walk in a Humvee in such a situation.
May the Lord protect us!