WASHINGTON — Former President Donald Trump offered a rambling and confusing explanation Monday of why he had reversed himself on whether the United States should ban TikTok over concerns that its Chinese ownership poses a threat to national security. In a CNBC interview, Trump said that he still considered the social media app a national security threat but that banning it would make young people “go crazy.” He added that any action harming TikTok would benefit Facebook, which he called an “enem