I think some in the administration here in Canada would legitimately seek the excuse that if the U.K. isn't moving as the principal duty holder under the Sino-British Joint Declaration with China, why should they? I've heard that argument.
Actually, the truth is, as Chung Ching rightly said, that this is a treaty launched at the United Nations, which means that the duty bearers are actually all of us, including Canada, so I think you're right to point out that issue.
There's something that has not been mentioned, but that Canada could certainly do. Hong Kong bizarrely enough remains a party to the International Covenant on Civil and Political Rights, which does have a dispute resolution mechanism. Any country could make a complaint under the ICCPR, and Canada should do so. They could do so. It might well result in China's withdrawing from the ICCPR, which I'd foresee as pretty likely. But that is not a reason not to do it. A complaint put forward under the ICCPR is something they can certainly do and lead on.
Thank you.