The 20th century saw the transformation of international law into a legal discipline concerned with the practical  application of law. It was fuelled by a manifold variety of treaties, procedures and institutions. Still, international lawyers persisted in conceiving and judging their discipline against a background coloured by national legal traditions. International lawyers did not overcome the optimist and evolutionary tradition based on the assumption that international law is but an ever closer approximation of national legal systems; nor did lawyers escape the fl ip side of this tradition, i.e., doubt and insecurity about international law and its basis. Rather than facilitating international law as a practical discipline, a superfi cial understanding of internationalism reinforced fetishisms of the discipline's theoretical past, not least the axiom that states only are proper subjects of international law. To a degree, international law has expanded at the price of becoming less separate from national law and national legal traditions.