Two centuries is somewhat arbitrary, because there are so many assumptions in the notion of "large scale nuclear conflict" as is. Areas that aren't direct targe

Two centuries is somewhat arbitrary, because there are so many assumptions in the notion of "large scale nuclear conflict" as is. Areas that aren't direct targets of nuclear weaponry will still suffer major setbacks, as supply chains for various goods and resources are disrupted. Present day problems, like hunger, access to medical care, and safe drinking water would just become magnified. For example, a nuclear conflict could potentially cascade into a much more dangerous famine, because supply for modern pesticides and agro-chemicals is temporarily destroyed. Supply chains for antibiotics could be disrupted, resulting in outbreaks of various preventable illnesses. If you total all the possibilities up, I suspect the secondary impacts of nuclear conflict would be worse than the actual warfare.