We only have 30 days worth of food in the US at a time. If people are rioting do you think companies will ship supplies anywhere? Even if food can get to stores and be protected there, how do you travel through rioters to get produce? Massive civil disorder will force food shortages, food shortages will increase civil disorder.... The circle of life continues...... AHHHH EAHNUA!
Civil unrest and full blown country-wide riots are two separate things. We had civil unrest during the Vietnam war and food was readily available. My version of civil unrest is localized and not sustained riots on a daily basis.
At the end of the day, the countries with the most money and most powerful military will be the best fed. Right or wrong, it is how it works.
Additionally, we have the potential to grow much more food than we do. It would take some time, but the thing I noticed is that when corn prices shot up, hundreds of fallow acres around our community were suddenly busting with corn - literally transformed in a single growing season. Captialism would lead people to grow whatever they could, not only to feed their families but to reap the windfall. Every time I fly over the US, I am amazed at the amount of land not used for anything, some has been lost to development but much still remains a potential.
Homeowners also have more land per family than most countries. We can all grow
something, a portion of our food. Where I live, tons of pink salmon go to waste every other year because nobody wants to harvest them. A few people do but not many as the quality is much lower than kings, coho or red salmon. Additionally, hatcheries could boost runs within a couple years if environmental concerns were trumped by hungry people. Just an example of what could be used if necessary. I think there is quite a bit of slack in the system - unless you live in NYC I guess.
Comparing this to Japan, Taiwan or other countries, we are in much better shape.