As with his predecessors, Trump’s power over the life and death of entire nations would be practically unbounded. Today, the nuclear deluge he could command would consist of thousands of weapons, each 10 or 20 times more deadly than the bomb dropped on Hiroshima. Nearly 2,000 U.S. strategic nuclear weapons aimed primarily at Russia and China (at a ratio of roughly 2 to 1), with additional dozens aimed at each of several other nations—North Korea, Iran and Syria—would be at a President Trump’s disposal from his first minutes in office. The city of Moscow alone lies in the bore sights of more than 100 U.S. nuclear warheads.
There are no restraints that can prevent a willful president from unleashing this hell.
If he gave the command, his executing commanders would have no legal or procedural grounds to defy it no matter how inappropriate it might seem. As long as the president can establish his or her true identity by his or her personal presence in the Pentagon’s nuclear war room or its alternates (places like Site R at Fort Richie near Camp David), or by phone or other means of communications linking him or her to these war rooms using a special identification card (colloquially known as “the biscuit” containing “the nuclear codes”) in his or her possession (or, alternatively, kept inside the “nuclear briefcase” carried by his or her military aide who shadows the president everywhere he or she works, travels and plays), a presidential nuclear decision is lawful (putting international humanitarian law aside). It must be obeyed as long as it is constitutional—i.e., the president as commander in chief believes he or she is acting to protect and defend the nation against an actual or imminent attack.
But within these broad constraints there is no wiggle room for evasion or defiance of the president’s orders. That’s true even if the national security adviser, the secretary of defense (who along with the president makes up the “national command authority”) and other top appointees and advisers disagree with the president’s decision. It does not matter whether the United States has already come under attack by nuclear or non-nuclear weapons. It does not even matter if the commander in chief simply orders the use of nuclear weapons on an ordinary day for reasons unknown to all but him or her. Under the president’s open-ended mandate to decide when the national interest is threatened, ordering up a nuclear strike is his or her prerogative, and obeying the order is incumbent upon the military servants of civilian authority.