Prof. Narang quoted in There was no legal way to stop Trump from ordering a nuclear strike if he wanted to, expert says
“The president alone possesses the sole authority to order a nuclear launch, and no one can legally stop him or her. Despite reports that Pelosi received assurances that there are safeguards in place in the event the president of the United States wants to launch a nuclear weapon, any such meaningful or effective safeguards would be illegal.”