Yes, I noticed that the CIA factbook map shows an area that includes southeastern China a small sliver of northeast India and Taiwan, but the likely reason for that is that it is difficult to show an actual map of Southeast Asia without also showing parts of the bordering countries.
I was just giving ya a hard time...looks like a strong beginning to a great paper.
Oh and you're probably right about the geography bit. I'm not surprised your teacher didn't even notice because I'm not sure geography or regional studies are studied extensively by writing teachers. I just happen to have had National Geographic maps substituting for wallpaper and three globes in the house when I was a kid and am a poli-sci geek