Here's a question rarely raised before Donald Trump ran for the White House: If the president ordered a pre-emptive nuclear strike, could anyone stop him?
The answer is no.
Not Congress. Not his secretary of defense. And by design, not the military officers who would be duty-bound to execute the order.
As Bruce Blair, a former nuclear missile launch officer and expert on nuclear command and control, has put it, "The protocol for ordering the use of nuclear weapons endows every president with civilization-ending power." Trump, he wrote in a Washington Post column last summer, "has unchecked authority to order a preventive nuclear strike against any nation...