As President Donald Trump continues to ratchet up tensions between the United States and North Korea through saber-rattling on Twitter and in television interviews, the U.S. has quietly begun preparing to put nuclear-armed B-52 bombers on "24-hour ready alert," a status not seen since the end of the Cold War. Commentators and national security analysts quickly denounced the reported steps as a severe and extremely dangerous consequence of White House "hysterics."