THE U.S. Supreme Court unanimously ruled this week that federal prosecutors could not use an international chemical weapons treaty to bring a case against a woman who tried to poison a romantic rival. The decision is a deserved rebuke to U.S. attorneys, who have a penchant for discovering a federal issue in garden-variety crimes.
The ruling set aside the conviction of Carol Anne Bond, who was convicted of trying to poison her best friend after she learned that Ms. Bond’s husband had impregnated the woman. Ms. Bond stole a chemical from the laboratory where she worked and smeared it on the other woman’s doorknobs, car door, and mailbox.
Ms. Bond could have been prosecuted in a state court, but the federal government took the lead after postal inspectors caught her opening the other woman’s mailbox. She was charged with violating a law passed by Congress to enforce the Chemical Weapons Convention.
In his majority opinion, Chief Justice John Roberts, Jr., wrote: “We are reluctant to ignore the ordinary meaning of ‘chemical weapon,’ when doing so would transform a statute passed to implement the international Convention on Chemical Weapons into one that also makes it a federal offense to poison goldfish.”
Ms. Bond’s victim was a human, not a fish. But the poisoning — which caused a minor burn on the victim’s thumb — was a federal case only in the creative imagination of prosecutors.
In one sense, this week’s decision was an anticlimax. When the high court accepted the case, some conservatives saw it as a vehicle for overruling a 1920 decision in which the court said that if a treaty is valid, “there can be no dispute about the validity” of a law passed by Congress to execute the treaty.
A reversal of that precedent was attractive to conservatives obsessed with the unlikely idea that the president and Congress might use the treaty power as a back-door way to override the federalism provisions of the Constitution. But in his opinion, Justice Roberts found no reason to reconsider the 1920 decision. He concluded that the prosecution was based on a clear misreading of the chemical-weapons statute.
There’s nothing wrong with the court deciding this case on the narrowest possible grounds. But if a future case poses the question directly, the court should rule that laws passed to execute treaties must accord with the Constitution.