I'm doubtful that "Capitalist nations" exist in the sense of nations founded on an ideology called Capitalism. My impression is that "Capitalism" was originally a pejorative term created by opponents to the established order and came over time to be adopted as a reaction by some of those being criticized to mean what they wanted it to mean. So we have an ongoing struggle over the meaning of the word, and reasoning based on a pretense of shared understanding of the meaning is not productive.

It's not as though someone wrote a Capitalist manifesto that initiated the practice of Capitalism.

You're conflating capitalism with colonialism / imperialism.