Ms. Meng was released on bail in Vancouver on Tuesday following a three-day public hearing that revealed the serious charges brought against her by the Justice Department. She is alleged to have lied to banks about Huawei’s ownership stake in a Hong Kong company that sold U.S. technology to Iran in violation of sanctions. There was nothing political about the case, or about Canada’s arrest of Ms. Meng; though she was detained on the same day Mr. Trump and Mr. Xi met to discuss the U.S.-China trade dispute, Mr. Trump did not know about the warrant.
China, however, reacted politically, describing Ms. Meng’s arrest as part of a U.S. campaign to contain China’s rising tech industries or force concessions in the trade talks. To punish Canada, which did no more than fulfill binding treaty obligations, it seized Michael Kovrig, a former diplomat who now advises the International Crisis Group, and Michael Spavor, who organizes cultural exchanges with North Korea. Neither of the Canadians has been heard from; they have received no court hearing or airing of the charges against them. Instead, Chinese officials cited the pretext that their organizations had not been registered under a repressive new law regulating NGOs.
Threatened by Beijing with economic boycotts on top of the abduction of its citizens, the Canadian government stood firm — only to be undercut by Mr. Trump. On Tuesday, in an interview with Reuters, Mr. Trump described the Meng case in explicitly political terms and linked it to the trade talks: “If I think it’s good for what will be certainly the largest trade deal ever made. . . . I would certainly intervene,” he said, adding, “It’s also possible it will be part of the negotiations.”
Mr. Trump has the legal authority to order a halt to Ms. Meng’s prosecution, but even the suggestion he would do so was wrong. It violated the norm under which presidents refrain from interfering in criminal investigations — a standard for which Mr. Trump has shown consistent disrespect. It sent China the false message that Ms. Meng’s arrest really was political, and that it can be reversed by political means, including the jailing of innocent Canadian citizens. It invited other governments who want something from the United States to take Americans hostage and then offer to make them “part of the negotiations.”
Mr. Trump is right to try to negotiate a trade settlement with China, but he should leave Ms. Meng out of it. Instead, he should demand that the Canadian prisoners be released and that a close U.S. ally not be punished for respecting the rule of law.