The atmosphere surrounding Brian Williams has turned so toxic that it’s not clear when—or even if—he’ll be able to return to the anchor chair. The original plan—Williams apologizes, takes himself off the air for a few days, schmoozes with Letterman, and slides back into his job—has crumbled. The apology was weak and inaccurate, too fleeting to heal the wound over telling a lie about his chopper in Iraq having been hit by a rocket-propelled grenade. His statement that he had decided as managing editor to suspend himself made it look like nobody at NBC is in charge, that he is...