My point is that sacrificing lives of American soldiers to promote democracy in others lands might be a losing enterprise.
If you're saying that Americans are responsible for Chamberlain's failings
I am not sure about "Chamberlain's failings" because UK at that times was not prepared or able to face Hitler. It was only after Hitler attacked Soviet Russia and failed to conquer it when he became vulnerable.
then I'm sure you'll have a hard time proving that Americans are responsible for everyone's choices everywhere!!!
One is reponsible for the things one puts on the plate. Now Americans own Iraqi problem and are responsible for it.
Without Wilson, Hitler would not get into power.