https://www.theamericanconservative.com/articles/mccain-and-the-pow-cover-up/
John McCain, who has risen to political prominence on his image as a Vietnam POW war hero, has, inexplicably, worked very hard to hide from the public stunning information about American prisoners in Vietnam who, unlike him, didn’t return home. Throughout his Senate career, McCain has quietly sponsored and pushed into federal law a set of prohibitions that keep the most revealing information about these men buried as classified documents. Thus the war hero who people would logically imagine as a determined crusader for the interests of POWs and their families became instead the strange champion of hiding the evidence and closing the books.