Anthea Roberts is a Senior Lecturer in Law at the London School of Economics and a Professor of Law at Columbia Law School.
I always enjoy reading Martins Paparinskis’ work and have read enough of it to know that I can count on him to have (1) written about questions that are of interest to me, (2) engaged in careful analysis, and (3) researched the hell out of the issue. Paparinskis’ breadth across investment treaty law, general issues of international law like state responsibility, and case law in specific fields like human rights law, is truly impressive. I don’t plan to push Paparinskis on his central thesis. Instead I want to ask three broader questions about how international law is developed and interpreted.
First, Paparinskis begins and ends his book by endorsing Jennings’ quote that the meaning of rules cannot be deduced a priori but instead “must be hammered out in the practice of Governments and by the familiar process of the development of law through its application by international tribunals” (pp 6 and 259). I agree with this point. In practice, however, we see extensive reference to judicial and arbitral decisions, including some that say they are interpreting treaty provisions as free standing norms and others that say they are interpreting the treaty in light of custom. But we see almost no discussion of the actual practice of governments, including in the latter type of case law. Why is that?
One reason is that the test for establishing custom is problematic. Customary international law is ostensibly made through state practice and opinio juris. But practice can be hard to find and cumbersome or difficult to collect. Paparinskis himself notes that the form of practice that we are most likely to see in the investment treaty context is pleadings by states, but this source has a number of shortcomings, including that pleadings are likely to be made by some states frequently and others rarely or not at all, and pleadings tend not to be made publicly available (pp 144-146, 171). (NAFTA is a notable and welcome exception to the latter point.)
Even when we can find smatterings of practice, it is almost impossible to collect real evidence of (1) general and consistent state practice followed out of (2) a sense of legal obligation. Even when people say that they are finding custom, they are usually relying on short cuts, such as referring to case law that says something is custom, General Assembly resolutions that declare something to be custom, or academic articles that opine that something is custom. Almost no one actually “finds” custom. Instead, arbitrators, academics and counsel typically refer to other sources that supposedly have already “found” custom.
The rules for determining custom are not a good description of what any of us actually do. Instead, they are largely used to critique the work of others. Read the rest of this entry…