Should We Annex Canada (and Mexico)?

In a conference in Brussels, Quebec's Premier Jean Charest "called for closer economic and trade ties among Canada, Mexico and the United States, saying the three North American countries should take the European Union as an example of closer integration."

In particular, Charest says the NAFTA countries should move toward "NAFTA-plus, that we should look at dispute settlement mechanisms that have binding effects on jurisdictions and whether we can open up to more trade and services and move forward. . ."

I doubt that Charest means that the NAFTA countries should try to emulate the proto-superstate that the European Union has become. But his comments do suggest that NAFTA dispute settlement provisions should become "binding" perhaps in the sense that they will be self-executing in the way that European Court of Justice decisions have become self-executing within Europe.

There might or might not be constitutional questions raised by such binding dispute settlement, but Charest's comments reminded me one of my favorite thought experiments: what would happen if the three NAFTA countries really did want to move toward a EU-style confederation? Is that even permissible under the current U.S. Constitution? I'm not sure. While the U.S. could surely welcome Canada and Mexico into the Union as states (just as Texas and Hawaii entered as foreign countries via treaties), I somehow doubt that is what Charest or the Mexicans have that in mind.