It's only ethical because we have no power to prevent their death. If research could be done that looked likely to extend lives, but we chose not to because we'd rather people die earlier, that's equivalent to stealthily killing them. We might as well be upfront about it, and have them slain for being too old, except then they'd tend to resist.
Right, so we have two competing ethical problems: extending life is good, but also, it removes the one (ethical) tool we have to handle the problem of accumulation of power in individuals. This is the conflict I'm grappling with. I don't have a good answer to the problem.
