By definition: No. Literally using the word "American" without meaning "everyone on human Earth" is a form of "us and them" thinking (and you can substitute any nationality and that would still hold true). In fact, even making a distinction between humans and non-humans like I just did is "us and them" thinking. I agree with the general principle that it's often a good idea to challenge "us and them" thinking, but I can't imagine the case for never being able to use "us and them" thinking