It’s time to talk about James Mattis’s involvement with the Theranos scandal

Former Defense Secretary James Mattis is back in the public eye with a book to promote, doing interviews and speaking in public about his career in government service.

That’s a golden opportunity to finally ask some tough questions about his prior service on the board of Theranos, a company that allegedly peddled fake blood tests and peddled connections to influential people in the national security world to get away with it for years.

Theranos was one of the largest business scandals of the past decades, described by the Securities and...