We don't need to engage in inter-generational griefingWhy not? A huge amount of post WW1 was about precisely that: generals trained for war on horseback, leading men into mechanised warfare. The 'never again' peace movement was a reaction. (wrong headed maybe, but this is how I believe it happened: it was inter-generational griefing.)
The EU exists because a generation of new voters emerged from the ashes of WW2 and said 'we're not going back there' -The election of the Atlee Labour government was the generation who fought WW2 saying "no" to churchill, from the generation who fought WW1 and the Boer war.
Inter-generational griefing is routine, normal and I would suggest neccessary. The succeeding generations have to seize control of the agenda, and stop the prior generations over-reaching their stated goals.