The Supreme Court ruled on Thursday in favor of two American corporations accused of complicity in child slavery on Ivory Coast cocoa farms. The decision was the latest in a series of rulings imposing strict limits on lawsuits brought in federal court based on human rights abuses abroad.

The case was brought by six citizens of Mali who said they were trafficked into slavery as children. They sued Nestlé USA and Cargill, saying the firms had aided and profited from the practice of forced child labor.

Justice Clarence Thomas, writing for an eight-member majority, said the companies’ activities in the United States were not sufficiently tied to the asserted abuses.

The companies, he wrote, drawing on the plaintiffs’ suit, “did not own or operate farms in Ivory Coast. But they did buy cocoa from farms located there. They also provided those farms with technical and financial resources — such as training, fertilizer, tools and cash — in exchange for the exclusive right to purchase cocoa.”

The plaintiffs said the companies “knew or should have known” that the farms were using enslaved children but failed to use their economic power to stop the practice. (The companies have denied complicity in child labor.)

The flaw in the plaintiffs’ case, Justice Thomas wrote, was its failure adequately to tie the companies’ asserted conduct to their activities in the United States.

That failure, Justice Thomas wrote, meant that they could not sue under the Alien Tort Statute...

...[T]he Supreme Court has narrowed the law in two ways, saying it does not apply where the conduct at issue was almost entirely abroad or where the defendant was a foreign corporation.

In 2013, in Kiobel v. Royal Dutch Petroleum, the court said there was a general presumption against the extraterritorial application of American law. It rejected a suit against a foreign corporation accused of aiding and abetting atrocities by Nigerian military and police forces against Ogoni villagers...