The international community has come a long way to develop a fabric of rules by means of treaties. While the effectiveness of this system generally is high, it is not easy to assess the impact of the handful of rules of the UN Charter that outlaw the interstate use of force. The absence of armed conflicts between great powers or other signs of restraints on the use of force may have been the result of other factors than the ban in the Charter, like fear of initiating nuclear war or fear of the economic cost of ruptures. The rule allowing force in self-defence only when an armed attack occurs has been under strain. Interventions have been undertaken, for instance to remove governments or to forestall nuclear proliferation. While unable to take enforcement actions, majorities in the UN General Assembly have been remarkably firm in an orthodox affirmation of the rules. Through interpretation there has also been some mitigation in terse rules. Thus, the prohibition of the interstate use of ‘force’ has not been taken to cover economic pressure and the right to self-defence ‘if an armed attack occurs’ may have regard to both past attacks and attacks deemed ‘imminent’ – but not to ‘anticipated’ self-defence.