ONUC's main goals stayed consistent from the first to fifth resolution. It aimed to both have Belgian military personnel (later expanding to mercenaries) withdrawn and to provide military assistance to ensure internal stability. The successive Security Council resolutions added to and elaborated on the initial mandate but did not fundamentally change the operation's objectives. These were especially significant because Belgium's invasion violated the norm of sovereignty, and the second objective was set to prevent the country from becoming a Cold War client state.