A diplomatic dispute has arisen between China and the U.S. after a Chinese unmanned airship was shot down over the Atlantic Ocean. CGTN talks with Su Jinyuan, a professor at Wuhan University's Institute of International Law, to discuss this issue from an international perspective. According to Su, the U.S. violated the rule of "every State must refrain from resorting to the use of weapons against civil aircraft in flight" in the Chicago Convention on International Civil Aviation of 1944, which is a core protocol governing airspace safety.