Comparativism and Constitutional Structure

I again want to thank Oona Hathaway for joining us in this discussion of her article Treaties’ End. As I mentioned in my opening post, her article is both rich in historical detail and deploys impressive empirical research. I will turn to the historical argument in a later post, for now I want to focus on an aspect of her article that I found especially interesting: her use of empirical research into how other states make treaties.

The results of Oona’s comparative research leads to some striking observations:

Only five other countries (Algeria, Burundi, Iraq, the Philippines, and Poland) require a legislative supermajority to ratify a treaty (p.136)

Only twenty-three states (including the U.S.) have different voting requirements for treaties than for domestic legislation (p.137)

The United States is one of only four countries (along with Ethiopia, the Philippines, and Tajikistan) that has less involvement by the legislature in treatymaking than in law making (p. 138)

Only Tajikistan and the United States have a lower level of legislative involvement for treatymaking than for legislation and “make the results of this process automatically part of domestic law in more than a few confined areas of law.” (p.138)

These results are quite persuasive that what the U.S. does is somehow different. But is what the U.S. is doing somehow wrong or unwise? My question, in sum, is what role should comparative analysis play in decisionmaking over whether or not to (continue the) shift from using Article II treaties to congressional-executive agreements? I don’t mean this question as a rehash of the debate over the use of foreign sources in statutory or Constitutional interpretation because what Oona is proposing is not a matter of interpretation, per se, but rather an argument about the function of types of Consitutional decisionmaking, that is, that agreements are a better policy option (more democratic, more effective, etc.) than the Article II treaty option.

But, to what extent is comparativism useful in this? As Oona persuasively argues, the current U.S. practice concerning the use of agreements versus treaties is idiosyncratic and based on the twists and turns of our Constitutional history. But couldn’t the same be said for any of these other examples? Treatymaking in each country is tied to its own history, its own idiosyncrasies. Aren’t how we make laws particularly immune to comparative approaches as they the result of a domestic bargain?(As opposed to, say, using comparativism to define what is a prevailing interpretation of “cruel and unusual punishment”)

So, even if the U.S. is a statistical outlier in how it makes treaties, should this matter?