During his Senate confirmation hearing in July 2014 to head the Department of Veterans Affairs, Robert McDonald pledged to “transform” the vast agency. After horrific reports of wait-time manipulation, coverups and even deaths at VA medical facilities across the country, veterans and the American people were calling for honest leadership to restore their trust in the department created to serve them.

Transformation wouldn’t be easy, Mr. McDonald said, but it was “essential.” And “those employees that have violated the trust...