The “west” comprises 3-4 entire continents (3 if you count South America) and over a billion people. The US alone accounts for 35% of the entire worlds military expenditure. There will never come a day, at least until man has colonized other worlds or the political and cultural map of the world is completely unrecognizable, when the “west,” taken as a whole, is geopolitically irrelevant.

This is like saying Asia will be geopolitically irrelevant. It just can’t happen due to how much of the Earths landmass and resources it takes up.