The open letter, dated Monday and addressed to Chinese President Xi Jinping, said its 141 signatories are “deeply concerned” by the detentions of Michael Kovrig and Michael Spavor by state security officials. The letter said Kovrig, a Canadian diplomat on leave to work with the International Crisis Group in Hong Kong, and Spavor, who organized outreach trips to North Korea, had advocated exchanges that help build ties around the globe.

The detentions “send a message that this kind of constructive work is unwelcome and even risky in China,” the group said. “We who share Kovrig and Spavor’s enthusiasm for building genuine, productive, and lasting relationships must now be more cautious about traveling and working in China and engaging our Chinese counterparts.”

The letter was signed by dozens of scholars and former envoys, including former ambassadors to China from Canada, Germany, Mexico, Sweden, the U.K. and the U.S. Among them were former U.S. Ambassador Gary Locke and ex-Hong Kong Governor Christopher Patten.

Huawei Arrest

The letter comes as Prime Minister Justin Trudeau urges other world leaders to speak out against Beijing’s actions in the aftermath of the arrest of Huawei Chief Financial Officer Meng Wanzhou on Dec. 1 in Vancouver. She now faces extradition to the U.S., where she is wanted in connection with alleged Iran sanctions violations. She has denied wrongdoing and has been released on bail.

China detained Kovrig and Spavor on Dec. 10, and has since sentenced a third Canadian man to death on a drug charge. The Canadians remain in Chinese custody, being questioned for up to four hours daily.

“We will always encourage friends, allies and thoughtful people around the world to point out that Canada stands up for the rule of law and all countries should stand up for the rule of law,” Trudeau told reporters Monday in response to a question about the letter. He said keeping justicial systems free from political interference had “served us well as a planet over the past decades.”

China has deflected questions about whether the cases were launched in retaliation, saying only that the men are being held by the country’s spy agency on suspicion of activities endangering national security.

Before the letter’s release, Chinese Foreign Ministry spokeswoman Hua Chunying dismissed Ottawa’s “empty show of strength” in trying to increase pressure on Beijing. “Canada should stop making irresponsible remarks,” Hua told a regular briefing Monday.

As Trudeau pressed for the Canadians’ release, his government was weighing whether to restrict or ban Huawei from its 5G networks. “We will make the decision that’s in Canada’s best interest and we will not compromise security,” Public Safety Minister Ralph Goodale told reporters in Ottawa on Monday.

China’s ambassador to Ottawa, Lu Shaye, warned last week there would be repercussions if Canada doesn’t make a “wise decision” on ultra-fast, next-generation wireless technology. On Monday, however, Hua said Lu “did not mean that China intends to interfere in the decision-making of the Canadian government.”

“We all know that Huawei is a leading supplier in the 5G technology, so losses are inevitable if Huawei is not chosen as a cooperation partner,” she said.

In their letter to Xi, the academics and former diplomats argued that holding the Canadians was hurting China’s efforts to resolve such disputes.

“That will lead to less dialogue and greater distrust, and undermine efforts to manage disagreements and identify common ground,” they said. “Both China and the rest of the world will be worse off as a result.” DM