This picture ironically sums up a good deal of why Americans and Germans, and Western Europeans for that matter, see the world differently (source: White House photo).
To put it into perspective, roughly 92% of Americans believe in God. As of 1992 only 56% of Germans feel the same. Americans attend church or a religious service nearly every week at a 41%-44% rate. Only 10% of Germans attended church regularly. (German statistics here)
Dennis Prager recently commented on the "Liberal Feelings vs. Judeo Christian Values" with an insightful article of the religious battle here in the United States. The same argument can be extrapolated to our European neighbors, and ultimately it affects how different nations see the role of morality in their foreign affairs.
Because the United States is still a religious nation, there is a clearer sense of right and wrong and less of a relativist moral view that the Europeans embrace. This ironically strengthens US Idealism in its foreign policy and surprisingly leads to short term European Realism in Europe. As this article in Germany's Der Spiegel magazine editorializes, even though it does not reach for the logical conclusion regarding America's religious beliefs affecting foreign policy, it asks the right question: "Could George W. Bush Be Right?"