It is an oft-repeated maxim that international law has undergone vast change in the modern era. (1) While it is self-evident that the rhetoric and preoccupations of international lawyers have indeed transformed from the positivist utterances of nineteenth century European diplomats, the discipline of international law has yet to articulate an adequate causal explanation for actual continuity and change in the legal expectations and obligations of the international community. The deleterious effects of this under-theorization are substantial. International law is stuck in a morass of contested doctrinal description. (2) Its content, effect, and very existence are grist for incessant academic debate and political wrangling. (3)
Indeed, the catalyst for the entire discipline of modern International Relations (IR) was the perceived moral and intellectual "great failure" of the international legal program during the period between the two world wars. (4) The human cataclysm of World War II, followed by the predominance of geo-political security issues during the Cold War era, prompted a great number of influential political and academic commentators to adopt realist assumptions which question whether international law is anything more substantial than an epiphenomenal symptom of liberal decadence. (5) More recently, the international acrimony associated with the United States' decision to invade Iraq, and centered at the United Nations (UN), has invigorated a strong current within the Bush administration for formal declaration of international law's irrelevance to the "problems of our time." (6)
Even among legal practitioners who accept customary international law (CIL) at face value, disagreement regarding its content is interminable. (7) While there is a common doctrinal terminology recognized by most international lawyers, these conventions are so malleable and theoretically self-contained that they often seem more a source of further tension in the law rather than grounds for mediation. (8) Lacking the tools to articulate or falsify causal claims about international law, legal publicists tend to invoke the term as a universal justifier for personal normative preferences. The effect of this cumulative contestation has been to give international law an air of conceptual abstraction that significantly undermines its credibility as a behavior-channeling factor in world politics.
Yet, international law remains an intuitively important concept. While IR scholars may be able to construct alternate terms calibrated to their particular modeling purposes, in the gritty world of policy and practice such academic concepts cannot entirely replace the operational and normative reality of international law. (9) At an operational level, states explicitly frame their actions in terms of--and energetically jockey over--its content. (10) At a normative one, our universal experience in domestic society is that none of the developments typically associated with liberal human progress--increasing economic activity and material well-being; procedural, non-violent political processes; reasonable community respect for human dignity--are sustainable without a robust and evolving societal "rule of law." (11) International law is, in short, the functional stuff that we have to work with in order to effect a civil and durable international society. It is thus a practically important task to ground it in a reasonably determinable, useful, and predictive theory of world politics.
Until relatively recently, such efforts were condemned to failure. The assumptions respectively underlying the dominant political and legal paradigms of international organization were too incompatible. International lawyers quibbled over the legitimacy and applicability of given legal norms while realist-dominated IR concerned itself with instrumentalist calculations of state interest--a conception of world order with little functional room for international law. …