Dumb, how? Cheated, how?
The impression other people get from the book is that Westerners were lucky, or fortunate, or blessed by geography and climate in a way that other peoples weren't.
I don't know if that's true or not, but it might lead students to think a little. And what's the alternative, anyway? That they succeeded because they were smarter than everybody else?
That they became predominant due to a culture of freedom and self-governance. They were fighting for hearth, home, and their own country, in a fundamentally different way than those fighting for an autocrat fight.
See Victor Davis Hanson’s Carnage and Culture, discussed briefly above. Strongly recommended reading.