There are rules in life and there are rules in life. The important thing is determining which rules make sense and which are simply a rule that has no purpose other than to be a rule. Rabbi Menachem Stem is a chaplain in the US Army which has Army Regulation 670-1 which makes illegal for anyone serving in the armed forces to have a flashy haircut or side burn and a beard. The reason for banning beards is obvious. Members of Islamic militant groups contain thousands of bearded fanatics and if in a combat zone that means shoot anyone with a beard. The good rabbi will be dealing with human relation issues far away from any combat, but the Army insists he can not wear a beard. Rabbi Stem has pointed out the army has given waivers to some Sikhs and Muslims but will not allow the nine active duty Rabbis to be other than clean-shaven.
As we note, there are rules and there are Army rules. Army rules, more often than not, make no sense. Ask anyone who has served in the armed forces of the United States. We doubt the presence of nine bearded men will cause tremendous loss of life in Afghanistan. Perhaps, the solution is for Rabbis with beards wearing uniforms decorated with a Jewish star of David. I have a hunch the Taliban will not don such uniforms.