“THIS CASE concerns allegations that a Nigerian corporation . . . assisted the Nigerian government in harming Nigerian citizens in Nigeria.” So begins a Supreme Court brief filed on behalf of Royal Dutch Petroleum Co., rejecting the claim that non-Americans can sue a foreign corporation in U.S. court for abetting human rights abuses committed in another country. Human rights advocates disagree, citing a once-obscure, 223-year-old law. The high court conducted a second round of oral arguments on the matter this week, and the justices appear poised to limit the law’s application. That’s good.

The first Congress seems to have passed the 1789 Alien Tort Statute to give federal judges jurisdiction over damages that foreign ambassadors suffer on U.S. soil and over piracy on the high seas. Three decades ago, judges began to read the vaguely worded law more expansively, spurring dozens of lawsuits relating to human rights abuses including arbitrary, prolonged detention; torture; and indiscriminate killing in Nigeria.

As intolerable as such offenses are, they do not obviously belong in U.S. federal court based on a convenient interpretation of an 18th-century law. The British, Dutch and German governments — none in danger of being labeled grave human rights abusers — worry that an expansion of U.S. courts’ jurisdiction will interfere with the prerogative of other nations to administer justice to their own citizens and redress wrongs committed on their own soil. John B. Bellinger III, a legal adviser to President George W. Bush’s State Department, points out that foreign governments might respond by encouraging a range of lawsuits in their courts against U.S. companies for, say, building drone aircraft.

In 2004 the Supreme Court limited the scope of the law, but it left an avenue open for judges to entertain cases involving foreign human-rights violations. This time around, the justices should be clearer in explaining the law’s proper limits.

Promotion of universal rights should be a driving concern of America’s foreign policy. U.S. courts can play some role in this, but Congress should be the body to define it. Lawmakers have authorized lawsuits by foreigners over certain abuses, such as torture. They can similarly authorize lawsuits against American individuals and corporations for abuses they commit abroad, specifying the circumstances under which U.S. entities might be held liable and the potential size of that liability. Better that than allowing the judiciary to create its own rules by means of a vague, centuries-old law.