Dependence on international aggression
Armed force may be used against the sovereignty and political independence of another state. It can take more shapes than declared or undeclared war. It may occur on the high seas in actions against merchant or naval vessels; it may occur in the air or in space, or on land in various ways. For example, the Nazis in World War II torpedoed merchant ships, invaded Poland, intimidated Austria into being annexed, rocket-bombed London, forced treaties, and allied themselves with three other aggressor-nations: Russia, Italy and Japan.