"The western world" in politics doesn't usually refer to geography, but to the high income euro-amerikkkan countries who benefitted from hundreds of years of theft (much from the countries you mentioned), who based themselves on individualism, private property, and capitalism, and prided themselves on their opposition to the collectivist policies of eastern countries.

This is why Cuba for example is not considered part of the western world, yet japan and south korea are.

Marxists also generally use the term "global south" or "the periphery" to refer to lower-income / exploited via unequal exchange, even though there are some "middle" / lower income countries in the global north also. It gets confusing I know.