In the early months of 2011 the peaceful protesters of the Qaddafi-regime were violently repressed by the Libyan authorities. The situation lead to the adoption of UN Security Council resolution 1973 on Libya, which authorized armed force to protect the civilian population. This thesis examines the principle of the responsibility to protect and its application in resolution 1973. Further, the thesis addresses whether the coalition forces implementing resolution 1973 have acted within the scope of the given mandate. The specific issues discussed are whether resolution 1973 justifies targeting of the Qaddafi-regime, whether the coalition forces were authorized to supply the Libyan rebels with arms and whether resolution 1973 permits the coalition forces to deploy ground forces in Libya.