The letter circulated by Huawei Technologies Co. was blunt. Canada was becoming dangerously entangled in the diplomatic feud between Washington and Beijing, it said, and there was only one answer: for Justin Trudeau¡¯s government to free the state-championed tech giant¡¯s chief financial officer and let her go back to China.

It sounds like a warning from the Chinese government. In fact, the June 23 letter to the prime minister was signed by a who¡¯s who¡¯s of 19 prominent Canadians ¡ª among them a retired Supreme Court justice, a former attorney-general and several ex-Cabinet ministers and ambassadors. Within 24 hours of it making headlines in Canada, Huawei executives were sharing the four-page note with journalists abroad.

The letter was meant to propose an answer to the plight of two Canadian men who¡¯ve been accused by China of espionage and whose grim captivity for more than 18 months has left the nation aghast. Instead, it appears to have hardened Trudeau¡¯s resolve, backed by an electorate that¡¯s no longer in a mood to see the government cut deals with Xi Jinping.