It depends what do you like to visit. Museums, I would go for Ottawa. Montreal does have some cool ones, but the capital city has more bigger ones like on nature, history, science, war and many more.
Art/culture, Montreal being bigger with more art museums (including the free Montreal Museum of Fine Arts), more historical sites and like Toronto a melting pot of ethnicity. Nightlife, Montreal has more choices but not all where you can speak in english. Ottawa does not roll up the sidewalk at 5 PM any more.
Nature, Ottawa does hva Gatineau Park on the Quebec side, but has some nice accessible parks, like Mont-Royal, Jean-Drapeau (site of Expo 67) and Lafontaine.
Both. But you should do it the summer, I guess. Montreal has better nightlife, cultural events, and a nice "old" downtown area, called Old Montreal where you can have a taste of France in North America; Ottawa has lots of history in regards to government buildings, museums, military, etc.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.