the inflexible anti-army social pressure is not from the society of frum American olim anyway. How much connection do you have with shtark Bnei Brak or Yerushalmi chareidim? Would you be in their shidduch circles in any case? My advice would be to try to convince your son to go with you to Rabbi Aharon Leib Shteinman (or any another gadol who is open to giving advice for some young men to have alternatives to full-time Torah study) and see what he will say.