Is the military by definition a rigidly masculine institution?

Many institutions in our country have been defined by a masculine construction--the presidency, education, etc. But in most of these institutions, leeway exists for women to enter these fields, and , if they wish, to form new, less masculine, definitions of these institutions. But I wonder if the military is so staunchly masculine, that it would be impossible, in the case of a gender-neutral draft, for women to have equality within the military. Ann Althouse has made arguments that would coincide with this idea.

If the military is inflexibly defined by a masculine construction, then women would , in the case of a draft, be the "sex slaves" of the military.