Many people who are not heads of state of nuclear powers can start a nuclear war, or respond with a nuclear weapon against a false threat. From Conn Hallinan at antiwar.com:
When President Donald Trump bragged that his nuclear “button” was bigger and more efficient than North Korean leader Kim Jong-Un’s “button,” he was perpetuating the myth that the leaders of nuclear-armed nations control their weapons. But you do not have to be Trump, Kim, Vladimir Putin, Theresa May, Xi Jinping, Narendra Modi, Mamnoon Hussain, or Benjamin Netanyahu to push that “button.” There are thousands of buttons and thousands of people who can initiate a nuclear war.
Indeed, the very nature of nuclear weapons requires that the power to use them is decentralized and dispersed. And while it is sobering to think of leaders like Kim and Trump with their finger on the trigger, a nuclear war is far more likely to be started by some anonymous captain in an Ohio-class submarine patrolling the Pacific or a Pakistani colonel on the Indian border.
In his book ”The Doomsday Machine: Confessions of a Nuclear War Planner,” Daniel Ellsberg says that the recent uproar over Trump’s threats to visit “fire and fury” on North Korea misses the point that “every president has delegated” the authority to use nuclear weapons. “The idea that the president is the only one with the sole power to issue an order that will be recognized as an authentic authorized order is totally false,” he told National Public Radio.
If a single “button” were the case, decapitating a country’s leader would prevent the use of nuclear weapons. Take out Washington (or Mar-a-Largo), Moscow, or Beijing and you would neutralize a nation’s nuclear force. In reality, the decision to use those weapons merely shifts further down the chain of command. The Russians call it “dead hand”: Moscow goes, and some general in the Urals launches an ICBM or the captain of a Borei-class submarine in the Sea of Okhotsk fires off his multiple war head SS-N-32 “Bulava” missiles.
To continue reading: Nuclear War: A Thousand Buttons