On the other hand our commander-in-chief (engineering expert that he is) has ordered the Navy to switch back to steam catapults on an already half-built carrier. That will also require bringing back 70 year old retirees. Pretty sure Trump would switch back to coal if he could find any living boilermakers.
I guess I'm the past, rulers old enough for that also usually collected enough other health issues to be largely inactive. I can think of a few cases where countries had to wait a year or so for the old ruler to die, but not another case where they were still active while demented. Maybe Ivan the terrible? https://en.wikipedia.org/wiki/Ivan_the_Terrible_and_His_Son_...
Sometimes bad ideas are just stupidity.