While the chairman of the Joint Chiefs is the White House’s top military adviser and the National Military Command System is charged with actually carrying out a launch order, the president is not required to check with them or get their assent before launching a nuclear strike…

During the end of President Richard Nixon’s tenure, his behavior was so erratic that Secretary of Defense James Schlesinger asked military officers to check with him first if Nixon gave a nuclear launch order.

Between the lines: There’s no clear way to create a nuclear command system that can act almost instantly without giving the president sole authority — which is why advisers like Schlesinger and Milley reportedly had to resort in a crisis to quasi-legal means to circumvent it.

Some experts have suggested the system itself is outdated and the risk of the U.S. facing a Cold War-style intentional first strike that requires an immediate response is far less likely than the chance of an accidental war — which sole authority arguably increases.