A year ago, Russia occupied Crimea, staged a disputed referendum about seceding from Ukraine and joining Russia, and annexed it to its territory. In postwar history, the annexation of a part of a sovereign country’s territory to the aggressor state has no precedent. There have been several occupations, invasions and secessions since 1945. But until a year ago no part of sovereign state was forcibly acquired by another state and made part of its sovereign territory. …