The United States made a somewhat clumsy entry onto the world stage during the Spanish-American War. The war in Cuba was short and decisive—and the rhetoric surrounding it was full of high ideals. But the Platt Amendment and the annexation of the Philippines revealed that American idealism was mixed with a hearty dose of self-interest, racism, and chauvinism. Not exactly the traits anyone wants to be known for. 

You might want to take this opportunity to explore the appropriate basis of American foreign policy. To what extent should self-interest guide American policies? And what are the self-interests that can be legitimately pursued? Protection for foreign markets? Access to raw materials abroad? Colonial possessions? Should American ideals, rather than self-interest, guide American foreign policy? What exactly are these ideals? Democracy? Christianity? Capitalism? And how aggressively should we attempt to "introduce" these to other people?