Sam: That’s a losing argument. If they made that argument they’d have to FULLY AND COMPLETELY accomodate ALL the halachic requirements of their conscripts. No kol isha. Davening b’zmano. 100% kashrus. No shomer negia violations. Sure. They’d far sooner badnChareidim from the army before they’d accomodate them like that. Secondly, we could still argue joining is against halacha on various grounds. Sakanas nefoshos violates halacha. Working on Shabbos is against halacha. And 1000 other things.
Concientous objections is a 100% legitimate claim. And one recognized by civilized militaries around the world. Hence the Amish, Quakers and others. Even atheists can claim concientous objections.