No national decision is as consequential, irreversible and fateful as the decision to use nuclear weapons. In the United States the president, and only the president, has the authority to order the unleashing of nuclear weapons. This power is not given by the Constitution, nor any specific law. It results from a series of Cold War-era decisions made secretly by the executive branch and the U.S. military.
This month, President Trump threatened China with the prospect of a remilitarized Japan if Beijing did not do more to push North Korea to end its nuclear and missile programs. Calling Japan a "warrior nation," Trump noted in an interview that he had warned China "you're going to have yourself a big problem with Japan pretty soon if you allow this to continue with North Korea."