Ok so here are some of the themes (topic sentences) that war of the worlds addressed. (One of my fav books btw ;P)
1. Foolishness and Folly - Some argue that the Martians are foolish for coming to Earth without protection. Basically the Mercy of Nature.
2. Fear - You could show the fear that Wells put into his characters.
3. Technology and Modernization - The Martians simply have better tech than 19th Century humans do.
4. Fate and Free Will - There is a lot of Biblical-sounding language in War of The Worlds