The U.S. government does not have the power to prosecute four suspected drug traffickers arrested in the territorial waters of Panama, the Eleventh Circuit held. The court found the prosecution was an unconstitutional application of the Maritime Drug Law Enforcement Act.

Confronting an issue of first impression, the court looked as far back as the Constitutional Convention in considering whether Congress even has the power under the Offences Clause in the first article of the Constitution to define and punish offenses of this sort.

The clause give Congress the power "to define and punish piracies and felonies committed on the high seas, and offences against the Law of Nations."

On March 1, 2010, the U.S. Coast Guard alerted the Panamanian Navy that it had spotted a fishing boat operating with no lights and without a flag heading north near Escondido, Panama.

Before the Panamanian officials closed in, the four defendants ditched their craft on the shore and fled on foot into the jungle. Within two days the defendants were apprehended and their nearly two-ton stash of cocaine was discovered.

Panama agreed to let the United States prosecute the four.

Federal prosecutors in Miami argued that under the Maritime Drug Law Enforcement Act, the U.S. could pursue suspected drug traffickers using boats in international waters and that Panama had authorized the prosecution.

A federal district court judge denied the defendants’ motion to dismiss the indictment, rejecting their arguments that the U.S. lacked jurisdiction and that the act was unconstitutional as applied to their case.

Ultimately all four defendants pleaded guilty, but reserved the right to appeal.

Eleventh Circuit Judges William Pryor and Rosemary Barkett, along with Northern District of Georgia Circuit Judge Timothy Batten, sitting by designation, reversed.

Although Congress isn’t necessarily bound by international law, it is bound by the Constitution. And under the Offences Clause, congressional power is limited by the law of nations — customary international law in modern parlance.

Even if Congress could define what constitutes customary international law, an elusive concept capable of confounding jurists and commentators, it does not have the power to create or declare offenses against the law of nations. Instead, Congress may only codify and explain offenses that are already offenses against the law of nations.

Furthermore, "if Congress could define any conduct as ‘a piracy’ or ‘a felony’ or ‘an offence against the law of nations,’ its power would be limitless and contrary to our constitutional structure," Judge Pryor wrote for the three-judge panel.

Therefore, the judges looked to international law to determine Congress’ power.

Aligning itself with five of its sister courts, the panel held that "customary international law is the general and consistent practice of states followed by them from a sense of legal obligation."

And drug trafficking doesn’t amount to customary international law by two measures.

First, drug trafficking historically is not a violation of customary international law. The founders contemplated only offenses such as counterfeiting foreign currency and violating laws of war to fall within its ambit. On the contrary, state-sponsored monopolies peddled opium across borders until 1909.

Nor is drug trafficking a violation of customary international law by today’s standards. This is true in the face of international treaties between countries that specifically address the problem.

For example, while 188 states are signatories to the 1988 United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, corruption and insufficient law enforcement in Central America and the Caribbean allow drug traffickers to operate with impunity.

Whereas drug trafficking is typically handled at the domestic level rendering treaties practically irrelevant, other offenses are largely reserved for the international bodies. The latter sort includes genocide, war crimes and crimes against humanity — clear violations of customary international law.

Specially concurring, Judge Rosemary Barkett went further than the majority. In her view, "when conduct has no connection to the United States, such as the conduct at issue here, it can only be punished as an ‘Offence against the Law of Nations’ if it is subject to universal jurisdiction."