For instance, I (in Europe) don't "lightly suggest" things in the US are difficult when it comes to guns/Trump/abortion/etc to American colleagues because these are sensitive political topics and nothing good can come out of that. You mentioned it was in South America so maybe another example would be to mention drug cartels and Pablo Escobar to Colombian colleagues.
I can imagine your Chinese colleagues thinking "here we go again..." and politely stirring the conversation to another topic.