An excellent (and for me, live) question on Facebook care of Mark LeVine, Professor of Modern Middle Eastern History at UC Irvine:

So, fellow academics — The new quarter/semester starts, you get an active duty or reserve service member in your class who might be deployed because of this nightmare Trump is so gleefully creating for us. Do you reach out to her/him and advise/urge/suggest that s/he refuse to deploy for anything related to a war with Iran, explaining that such a war would be a crime against humanity? Or do you wait for them to come to you if they so choose?

My answer:

Something half-way between: start up a conversation outside of class time where you explicitly raise the issue and challenge any false assumptions. Obviously, [this] has to be done with a certain degree of tact if it’s going to work at all.

In other words, my own approach is not to offer prescriptions per se (certainly not to lead off with them) but to play an essentially Socratic role, and let students wrestle with the prescriptive implications. I say “outside of class time” because I do think there has to be a firewall between classroom instruction and political activism, and also between the instructor’s formal professional role as instructor and his or her informal (but still permissible) role as on-campus Socratic interlocutor. But to paraphrase Willie Sutton: there’s no avoiding antiwar activism on campus, especially on a military-friendly campus; that’s where the cannon fodder is. (Of course, in practical terms, most of my military students are veterans no longer actively deployed, but the issue can and does still arise for reservists.)

There’s a good discussion taking place at LeVine’s Facebook page on a public setting.