I have discussed FOOD issues on this blog and will again. Another factor to me in the global instability now is the huge level of unemployed and underemployed which combine in the US to be just under 20% of the population 18 and over.
Go to this fascinating graphic:
To me FOOD and EMPLOYMENT or the lack of one or both is the key economic indicator for stablility in any given geographic area or nation-state. I could be wrong of course since religion is also a force for instablilty IMO but not equivalent to FOOD and EMPLOYMENT normally in its impact on stability and governance.