Japan is not in "the West." It also has a relatively small population; it's only a third of the size of tye US, and less than a tenth of either China or India. Germany's population is flat, but it's even smaller than Japan. France's population is growing. Spain's is declining slightly, but its even smaller than Germany - half the population size! Overall, the total rate of population change in the combined EU is a fraction of the number of new people the US added, and a drop in the bucket compared to the total growth of the overall World population.

Were you suggesting that anti-aging technology should only be available to people in the wealthier countries? Because those are almost the only ones with flat or negative growth. If everyone has access equally, then there will be a population explosion and crisis, because the countries adding the most people to the world right now are also the largest - by orders of magnitude.