he coronavirus has focused the world’s attention on the woeful lack of ventilators, respiratory masks, and intensive care unit beds available in many countries. Far less attention has been paid to another pandemic-driven shortage lurking over the horizon: food. As trade walls go up and governments panic about preserving their own food sources, the coronavirus threatens to disrupt global supply chains. Russia, the world’s largest wheat exporter, is limiting grain exports from April to June. Egypt, the world’s biggest wheat importer, has ramped up grain purchases and stopped exports of legumes. The looming food shortage has an echo of the...