> End of civilization takes a lot more than high oil/fertilizer prices,

Energy prices factor into everything else, so there literally will be a lot more than higher oil/fertilizer prices.

The end of civilized relations between countries is a sign of sick and dying civilization and we are there already, plenty of other evidence too.

> even if it causes famine in poorer countries.

So compassionate of you.

In the worst there will be some people dying, a lot of people get poor and maybe democracies will be replaced by feudal structures. It's still far away from the end of civilization.