I have no doubt that most Americans have realistic assessments of their interests in and knowledge of world politics, as reported in this study: they don’t know much about it and they don’t care. Americans are practical people and many Americans can travel 500 miles in any direction and still be in the United States. Such knowledge really doesn’t have much use in their day-to-day lives.
I wouldn’t be surprised if many Frenchmen had some notion on Spanish politics or if Italians had knowledge of German politics. How much knowledge do Europeans have about Japanese politics?