Why don't women go to the military?
Selective Service law as it’s written now refers specifically to “male persons” in stating who must register and who would be drafted. For women to be required to register with Selective Service, Congress would have to amend the law.
The Supreme Court
The constitutionality of excluding women was tested in the courts. A Supreme Court decision in 1981, Rostker v. Goldberg, held that registering only men did not violate the due process clause of the Constitution.