A system of checks and balances exists to prevent a U.S. president from illegally ordering a nuclear strike, but no one can stop the commander in chief from using nuclear weapons, according to senior military experts and a former vice president.
"If President Trump were to decide that it's time to put (North Korean leader) Kim Jong Un in his place once and for all, he would choose a plan that already exists. And it would be almost impossible in my view to override a decision to implement that option," Bruce G. Blair, a former nuclear missile launch officer and co-founder of the Global Zero group that advocates eliminating nuclear weapons, told USA TODAY on Sunday.
The exact procedure that would be followed has come under scrutiny amid congressional testimony about Trump's experience and authority to wage war at a time of elevated tensions with North Korea over its nuclear ambitions.
"We are concerned that the president of the United States is so unstable, is so volatile, has a decision-making process that is so quixotic, that he might order a nuclear weapons strike that is wildly out of step with U.S. national security interests," Sen. Chris Murphy, D-Conn., said at a hearing last week into presidential authority to use nuclear weapons.
While the key aspects of the precise sequence of events that would allow a U.S. president to launch a nuclear strike remain a mystery, Gen. John Hyten, the current head of Strategic Command, said Saturday at the Halifax International Security Forum in Canada that he would refuse a launch order from a president if he believed that order to be illegal. He added that the president would then likely ask him for legal options.
"I provide advice to the president," Hyten said. "He'll tell me what to do, and if it's illegal, guess what's going to happen? I'm gonna say, 'Mr. President, that's illegal.' Guess what he's going to do? He's going to say, 'What would be legal?' And we'll come up with options of a mix of capabilities to respond to whatever the situation is."
However, Brian McKeon, a senior military policy adviser in the Pentagon during the Obama administration, effectively told U.S. senators during congressional testimony that a president's will to launch a nuclear strike could not be thwarted.
He said that if a military commander refused to execute the president's order the defense secretary would then be told to order the reluctant commander to proceed.
"And then, if the commander still resisted," McKeon said, "you either get a new secretary of defense or get a new commander."
Either way, the launch goes ahead.
"The protocol for ordering the use of nuclear weapons endows every president with civilization-ending power," Blair wrote in a Washington Post column last summer. And the president "has unchecked authority to order a preventive nuclear strike against any nation he wants with a single verbal direction to the Pentagon war room."
Blair told USA TODAY that "no one ever thought that a commander of Strategic Command would ever be thinking of defying a president. The whole system was set up to be extremely streamlined. When I was a nuclear launch officer I practiced fighting nuclear wars probably 100 times in a simulator and exercises in the field scores of times, and the launch order always came directly from the Pentagon."
Speaking to Fox News in 2008, then-vice president Dick Cheney said: "(A president) could launch a kind of devastating attack the world's never seen. He doesn't have to check with anybody. He doesn't have to call the Congress. He doesn't have to check with courts. He has that authority because of the nature of the world we live in."
Blair outlined this process to launch a nuclear strike:
1. The president consults with his advisers. They explain his available options, and the Strategic Command chief located near Omaha, Neb., gives a recommendation.
2. The president chooses an option and orders the Pentagon war room to implement it.
3. The Pentagon war room asks the president to authenticate the order using a code, the so-called "biscuit."
4. The war room formats and transmits a launch order that is the length of a tweet directly to executing commanders in submarines, to those overseeing land-based rocket missiles in the mid-Western U.S. and to bomber forces.
5. The launch order is checked for its authenticity by commanders using special codes that they already possess.
6. The launch orders are transmitted to all commanders around the world simultaneously.
7. If the codes are authenticated, the land-based weapons are fired within a minute or two and within 15 minutes for submarines.