Ukraine is a major exporter of key food staples around the world. Even before Russia's invasion of Ukraine, the prices of food commodities like wheat were near all time highs. Since the outbreak of armed conflicted, these prices have soared even higher.  What impact is this war having on global food supply, food prices and food security? I put this question and more to Joe Glauber, Senior Research Fellow at the International Food Policy Research Institute in Washington and formerly the chief economist at the United States Department of Agriculture.