May the President of the United States command state courts to re-open criminal proceedings pursuant to the determination of the International Court of Justice (ICJ)? The question is not (yet) at the heart but within the ambit of Medellin v. Dretke, pending before the U.S. Supreme Court.

Under the 1963 Vienna Convention, which the U.S. ratified in 1969, member-states must “without delay” notify foreign countries of the arrest or detention of one of their citizens. It’s the kind of treaty we like on account of its reciprocity: we want to know when Americans are detained in strange places, such as Belgium. But criminal law in the U.S. is usually enforced by states. What happens when states neglect to notify the proper foreign authorities, which is not uncommon?

Mr. Medellin, a Mexican national, was sentenced to death in Texas courts for gang rape and murder. He filed the predictable federal habeas petition arguing, inter alia, that his consulate hadn’t been properly notified. The district court and Fifth Circuit waved that argument and others aside, because (a) Medellin was in “procedural default” (having failed to raise the claim at trial) and (b) the Vienna Convention is a matter among governments; it doesn’t confer private enforcement rights. Meanwhile, the ICJ, in the Avena case involving 51 Mexican nationals in the U.S. (including Medellin), held that the U.S. must review and reconsider the convictions in all these cases.

Now it gets complicated: when Medellin cranks his case into the Supreme Court, the administration (a) informs the Court, in this brief urging the Court to dismiss the case, that it has “determined” that “the state courts are to recognize the Avena decision” and (b) notifies the United Nations that the U.S. is withdrawing from the Vienna Convention.

Urging dismissal is plainly correct, both because it’s legally compelling (for more see Julian Ku’s terrific stuff at http://lawofnations.blogspot.com) and because the only thing that could be worse than an ICJ ruling is a Supreme Court ruling, especially in a case involving the death penalty and international law.

Withdrawing from the Convention is a shame but politically understandable. The blame here falls squarely on the anti-death-penalty crowd, which pushed this issue until the administration was left with a choice of either withdrawing or else, surrender the Constitution to the ICJ—in other words, no choice at all.

In contrast, the presidential “order” to the state courts (whose legal status is not at all clear) is really quite breathtaking. AsDoJ describes the order, it simply “preempts” state law, including procedural default rules that would otherwise bar judicial reconsideration. That’s an aggressive but plausible assertion of presidential authority. But the order actually goes further. “Preemption” is an exercise of federal supremacy that simply tells state authorities not to do X, Y, or Z. But the order here purports to command the Texas courts that they must affirmatively do A, B, and C—as outlined in the ICJ’s Avena disposition. That’s not preemption but commandeering. There’s a potent argument that the Constitution forbids it.

Medellin’s lawyers have moved to dismiss their Supreme Court petition. The Texas courts are probably awaiting instruction from the Supremes. Texas Attorney General Greg Abbott has publicly stated his position that the President’s order is in conflict with constitutional principles of federalism. To our minds, he has a point.