It depends if you want to do something more modern, or something historical. If you do something historical, it's going to be a situation that's already settled, most likely. You could argue whether the American Revolution was actually the only way for Colonial Peace. The Moderates felt we should have reasoned with Britain. Historians still go back and forth about what the American Revolution really was.
You can also talk about Napoleon. Was he really looking for Global Domination? (I personally don't think so, providing he didn't start majority of the wars France was in.) What did he do for France?
You could go on about why America should have listened to Patton and gone right through to Russia after the fall of Nazi Germany, and totally evaded the Cold War Era.
If Military History isn't your thing, you can always talk about McCarthyism and the threat of Communism in America. If you need other ideas, feel free to e-mail me.
