ICC jurisdiction over the Crime of Aggression activated: On this day the International Criminal Court can finally begin exercising jurisdiction over the crime of aggression. We now have, for the first time in history, a permanent international court with jurisdiction over the crime of aggression – the worst form of the illegal use of force. And indeed, the moment could not be more auspicious. The provisions on the legality of the use of force – a centerpiece of the United Nations Charter – are frequently challenged these days and at times openly ignored. The conviction that armed conflict between States was largely a phenomenon of the past has been replaced by concerns that international armed conflicts may be back on the rise. We therefore, more than ever, need a strong, independent, international Court with jurisdiction over the most serious forms of the illegal use of force.