Jared Diamond's arguments in Guns Germs & Steel are quite complex. He proposes an "anthropological" explanation of why Europe became dominant in terms of power. He explores lots of other cultures, but ends up concluding that Europe developed as it did because of a confluence of factors:
- geography
- food production
- development of ancient crops (what's more suitable)
- domestication of plants / big annimals
- evolution of germs (and how that relates to the domestication of animals)
- evolution of writing
- evolution of technology
- religion and government
Basically, lots of areas of the world had SOME of the factors that he identifies (such as large animals suitable for domestication), none, except for Europe, had all. So as a result, while some cultures were quite advanced, they never either a) required or

desired to leave their ancestral homeland and colonize, resulting why Europe had all the colonies and everyone else was colonized.
In explaning Canada/US, the similarity of the geography, climate and ecology to Europe resulted in successful colonies, whereas other areas were much less successfully colonized.
Overall, I think it's a very balanced view.