Well, it shows you how much I know. I just assumed that Americans didn't sell or wear poppies. I assumed it was mostly the practice of European and Commonwealth countries.

You bring up a very interesting question about what kind of effect WWI might have had on the US if they had suffered the same kind of losses as other countries. It's possible the US might be more cautious, but it's also possible that it would be even more militant. I mean, look at the reaction to 9/11. Another country might (and I say might) have ended any kind of military operations overseas. However, if anything, I think 9/11 caused the opposite to happen.