Many today seem to have forgotten that the original idea for building a united Europe was to establish an international political system suited to purport peace, stability and growth for all nation states, regardless of their military might, or their economic and political power. The projects discussed in this study were targeting at bringing about a new era of peace through the restriction of national sovereignty. The people who drafted these projects were no lesser than the greatest philosophers of Europe, among them Abbé de Saint-Pierre, Jean-Jacques Rousseau, Immanuel Kant, Saint-Simon, and Count Coudenhove-Kalergi. The study shows that world peace is conditioned upon the restriction of national sovereignty, one of the most dangerous concepts of international law. It is an idea that goes back to the Renaissance and was drafted mainly under the pulpit of Jean Bodin and Niccoló Machiavelli. No other concept in international relations has cost the lives of so many victims of war, wherever in the world. Besides, it is alien in today's international network culture and at a time where the relationship ruler-vassal has become one of government-citizen. When nations understand that in a networked international community, any war means auto-destruction by implication, the need for the restriction of sovereignty through the establishment of a supranational authority or world government becomes obvious.