That may be, but we weren’t in them. Britain, France and others were................
I was under the impression that China was miffed at the U.S. for being part of the sales within China. And also the treaty specified that if Americans were caught selling it in China then they could be tried by only Americans. Thus, the Chinese today see the U.S. as part of their beginning of their Century of Humiliation that they’re trying really hard to remove their shame of (by being dominant).