Is the same true with military service members?

Employers are free to establish dress codes for employees and enforce them with firing if they desire to.  The exception is, if the violation of dress code, is due to a religious reason, such as the wearing of a scarf, you may not discipline the employee because the courts have considered that allowing the wearing of scarfs as not an undue hardship. Is the same true with military service members? Please Explain at least 100 words

Reference- Bennett-Alexander, D. & Hartman, L. (2015).  Employment law for business (8th ed.). New York: McGraw-Hill Education

I need answer today not tomorrow.