North Korea announced on Tuesday that it had successfully tested an intercontinental ballistic missile (ICBM), which state media said had reached an altitude of 2,802 kilometers, its highest ever missile test. China and Russia have called for concessions in response but the US opted to engaged in a joint military exercise with its South Korean ally. Today we ask why North Korea has embarked on this increasingly aggressive military stance, how it developed this capacity and whether its threat of a nuclear payload is real.