I would use the definite article when using the term to refer to the country as a whole. Such a thing is done when making generalizations. Example: "The Americans are a gregarious people." It's tricky though, because with the example I just gave you don't really need the definite article (the). However, with British and Swiss (which don't really have singular forms) you do need the definite article (the). You might need the definite article to distinguish between groups. Example: "The Americans met with the British." You don't need "the" if you are using another qualifier. Example: "Quite a few Americans visit Canada every year."Originally Posted by tianshan
I hope that helps.