China is blowing the geopolitical opportunity of a lifetime. There has probably never been a better moment to undo America's greatest strategic advantage by dividing the United States from its global network of democratic allies, many of which are horrified by President Donald Trump's rhetoric and policies and deeply worried about Washington's staying power. Yet Beijing is doing its best to remind the world that it has far more to fear from a hegemonic China than from an erratic America.

The latest example is China's response to the detention of Meng Wanzhou, the chief financial officer of Huawei, in Canada. The timing of that arrest, on charges of violating bank laws and U.S. trade sanctions, surely struck Chinese officials as suspicious. It came on the same day Trump met with President Xi Jinping in Buenos Aires, amid high U.S.-China tensions in an ongoing trade war. Yet — some unwise comments from Trump notwithstanding — there is no indication that this was anything other than a legitimate effort to enforce U.S. laws that Huawei had broken. Canadian authorities simply would not have made the arrest otherwise.

The New York Times described China's official reaction to Meng's arrest as "measured." In reality, it has been anything but. Beijing has responded with a modern form of hostage-taking, detaining two Canadians (and, according to reports on Wednesday, possibly a third) on what appear to be spurious charges. The hawkish, quasi-official newspaper Global Times has implied that citizens of other "Five Eyes" countries (the U.S., U.K., Canada, Australia and New Zealand) might face the same treatment. Arrest one of ours, China is saying, and we'll snap up two of yours.