China, France, Russia, United Kingdom, and the United States are considered nuclear states with demonstrable abilities to assault other nations with nuclear weapons. India, Israel, North Korea, and Pakistan could probably do it to, albeit it with limited arsenals. But just how hard is it to push the figurative red button.
Stanislav Petrov was duty commander for the USSR rocket forces. His job was to monitor the satellites launches from American ICBM forces. On September 26th 1983 one was detected, then there were four more.
‘An alarm at the command and control post went off with red lights blinking on the terminal. It was a nasty shock. Everyone jumped from their seats, looking at me. What could I do? There was an operations procedure that I had written myself. We did what we had to do. We checked the operation of all systems – on 30 levels, one after another. Reports kept coming in: All is correct.’
Petrov's duty was to warn Soviet high command. If an ICBM had been launched from a US ground launch site, it would take about 30 minutes to reach the USSR. The Soviet commanders would trust his launch recommendation. Petrov was skeptical of the system readings though. He also knew that logically the US would never launch just five missiles against the USSR and await retaliation. First strike doctrine was that you fired everything you could at the enemy in hopes of blunting the response. So Petrov refrained from letting his superiors know until he could correlate his information against other sources. It was found that, due to computer faults, what he had been detecting were actually flashes of sunshine on the tops of heavy clouds.
Two years earlier in the United States, Harvard law professor Roger Fisher published a thought experiment. ‘My suggestion was quite simple: Put that needed code number in a little capsule, and then implant that capsule right next to the heart of a volunteer. The volunteer would carry with him a big, heavy butcher knife as he accompanied the President. If ever the President wanted to fire nuclear weapons, the only way he could do so would be for him first, with his own hands, to kill one human being. The President says, “George, I’m sorry but tens of millions must die.” He has to look at someone and realize what death is—what an innocent death is. Blood on the White House carpet. It’s reality brought home.’