Setting aside nationalist reactions for a moment, long life extension would have a huge impact on global society.

• When an older generation passes on, their active ability to shape society goes away, and the new generations are able to define the values, laws and morals of the era. Every idea we have--science, medicine, law, urban design, agriculture, art, entertainment, literature-- grows and changes thanks to new players joining society and making their mark. An undying elite could put all areas of thought and progress in a stranglehold, calcifying society in the vision of the undying.

• Wealth is passed on upon death, but these undying would continue to hoard wealth, becoming powerful billionaires and using their power to distort society to their vision.

• A Greek proverb says "Society grows great when old men plant trees whose shade they will never sit under." What happens when that calculus changes? The elderly generally do not have and raise children. Especially if they've already had children, they tend to focus on other activities, hobbies, leisure, cruises. They also have to go to the doctor more often. If the cohort of undying became large enough, it would start demographic trends where more resources are expended to meet these needs of people who are not interested in the future of society, but only the continuance of the short term present.

To some extent developed countries have already experienced this change on a longer time line, with the advent of modern medicines increasing lifetimes from about 30 years to over 80 within a few generations. Nursing homes didn't used to exist. "Cancer Survivor" is a relatively new term. The implications of near immortal levels of life extension are far more broad reaching than I can do justice in a few simple paragraphs, but just consider what might happen in an old growth forest if the oldest trees never fell to became nurse logs for the next generation.

You would actually have a problem if life extension is outside of the scope of workforce participation, regardless of the source. That issue would make life extension elitist, and it would ultimately devolve into feudalistic fascism. Democracy requires a fundamental measure of egalitarianism. Life extension is essentially a new race of humans. That would reset the social evolution to such a degree we'd probably need a millennium to get it sorted.

I mean all the west is already pro young death, so the insurance companies could pocket the retirement and healthcare funds. Places like Kkklanada even actively promote assisted death.