The ‘socio-legal’ has always been a vigorously contested space in International Law theory. The ‘legal’ has been consigned to near-irrelevance by realist international relations theory on the one hand, and lauded as a remarkable achievement of modernity on the other – a civilising enterprise aspiring to the preservation of peace by the State under the rule of law. The instrumental role of International Law in achieving the peace is now being reoriented by liberal institutionalists such as Anne Marie Slaughter. This theory postulates a regime of international, or at least transnational, law formulation through the interaction of networks of non-state actors such as domestic courts, regulatory agencies, executives, NGO’s and other discursive communities. There is a ‘thicker’, more diverse set of international relations which erodes the sovereignty of State from without and within. Globalisation can be characterised as a context and a vehicle for this new liberal-cosmopolitan project. The theory is not limited to procedural innovation, however, for it carries within it the specific telos of liberal internationalism, or in its strongest form a liberal millenarianism which aspires to something like a Kantian peace in an expanding zone of liberal law. If there is an ongoing tension in International Law theory between the theory and the practice then this new liberal institutionalist approach at least has the virtue of claiming to describe practice. However, its teleological claim must bear closer scrutiny from perspectives of both theory and practice. Is it really ‘new’ or just a light shone more brightly on old practices? Is there such a fundamental shift as to amount to a disaggregation of the State and an undermining of the centrality of the State in the global order? Do these networks represent something authentically ‘liberal’ or are they merely opaque, unaccountable, self-selecting elites? Are they really just a kind of vulgar interest-group liberalism or do they represent an embryonic civil society? Finally, can or even should liberalism make any claim to a post-historical space that leaves the non-liberal world mired in ideological backwaters?