Congress has expanded the categories of people entitled to citizenship at birth. The relevant statute lists eight categories, for instance granting citizenship to babies born in unincorporated U.S. territories to at least one American parent. This applied to the late Sen. John McCain, who was born on a U.S. naval base in the Panama Canal Zone. Concerning the question at issue here, though, the law is clear but not explicatory, borrowing the 14th Amendment’s language: “a person born in the United States, and subject to the jurisdiction thereof.”

With this judicial and legislative lack of clarity, an executive order is perfectly proper, perhaps even necessary, to instruct executive-branch officials and agencies not to confer birthright citizenship except when Congress or the Supreme Court has mandated it. To say that an executive order is necessary and proper, though, does not mean it fully settles the matter. The issue of birthright citizenship should be part of a larger legislative package focused on strengthening the U.S., its security and its economy.

Few developed nations—and none of the countries of Europe, which many Americans want to emulate—practice the rule of jus soli, or “right of the soil.” More common is jus sanguinis, “right of blood,” by which a child’s citizenship determined by parental citizenship, not place of birth.