Which part of the vow makes it possible for jainis to serve in the military?

I do solemnly swear that I will support and defend the constitution of the United States.

United states v.  nixon, 418  u.s.  683 (1974),  was  a landmark  united states supreme court case  that resulted in a unanimous  decision  against president richard  nixon, ordering him to deliver tape recordings  and  other subpoenaed materials to a  federal  district  court.