Under pressure from the US government, TikTok is now facing the music with the possibility of a nationwide ban if it defies a government order to sell to an American company — unless the popular social media app can convince a high-powered panel that its data security restructuring plan sufficiently guards against national security concerns. At the heart of this social media business and national security drama is the increasingly tense relations between the US and China. The video-sharing platform with 150 million US users is best known for quick snippets of viral dance routines and has been under scrutiny…