Analysis is offered the UN Charter articles, notably Art. 2:4, that relate to the use of force. The Friendly Relations Declaration adopted by the General Assembly in 1970 is a useful tool of interpretation. The forcible seizure of territory is found to be a primary objective of the ban on the use of force. Post WWII, such seizures have been uncommon, but a few are cited. Interventions are of different kinds and many – that contain elements of force – fall under the prohibition in Art. 2:4. The term ‘force ‘does not cover ‘economic pressures’ but may cover various kinds of cyber-attacks. What the ban on ‘threat’ of force covers has not yet been authoritatively clarified. As only force ‘in international relations’ are covered, the article does not restrict governments’ use of force inside their own territories but it does prohibit foreign interventions supporting rebels. The case of the civil war in Syria and the interventions in it is discussed.