The interaction between international and domestic legal systems underwent a deep structural change. By means of a literature review concerned with a critical approach of International Law, this Article presents three perspectives: Modern, Imperial Post-Modern, and Deconstructive Post-Modern. Traditional international law scholarship emphasizes the first and the second trends, while this Article presents the third. While the first frames these interactions on the monism-dualism debate, the second establishes an international law prevailing unconditionally over domestic law, international human rights. The third criticizes whether it is still proper to search for an a priori solution for this interaction. By rejecting global governance and the truly common law as alternatives to imperial post-modern international law, this Article emphasizes that legal analysis should identify, stimulate and reinforce the a posteriori customary normative spontaneity of multitude. This Article argues that a serious post-modern international law should be guided by a radical political drive of law, foster a deconstructive interaction of different—spatial, temporal or thematic—representations of law and reject traditional hierarchical solutions and any kind of previous, single and exclusive—national or international—authority between any legal order.