Consider the scale of the living standard drop Robin is predicting: roughly an order of magnitude. That's much larger than the great depression - which set the stage for WWII. A prospect of an order of magnitude drop in living standards would probably be enough to trigger wars of extermination. To put it another way, a cross between "Strong Security" and a policy by population-limiting nations to limits the populations of neighbors as well (with nukes if needed) could be stable.