CBS News got an up-close, mid-air view of the complex tensions playing out between China, its ally North Korea and the West in the East China Sea, on board a Canadian surveillance aircraft enforcing UN sanctions against North Korea's nuclear weapons program. As the Canadian aircraft checked a North Korea Korean ship that may have been carrying goods banned under the nearly-20 year-old sanctions, Chinese jets flew up close in what was seen as an act of calculated intimidation. #china #northkorea