A number of these countries experience severe droughts that last for years. By increasing food production in areas where growing food is easier, there is more food available to send to poorer nations. Additionally, many populations depend on subsistence farming. Growing crops with a potential for higher yields will allow these people to better feed themselves. Crops can be genetically modified to contain genes that will manufacture vitamins or other essential nutrients so that problems with malnutrition or vitamin deficiencies are greatly reduced or even eliminated.
Genetic modification is nothing new.
Humans have been influencing and changing the genetics of food crop for thousands of years using selective breeding and hybridization. For example, today's corn bears little resemblance to its historical progenitors. It has been selectively bred to produce larger, better ears of corn. Humans have successfully used selective breeding and hybridization with virtually all crops and livestock. New GM varieties have been more extensively tested than any foods in history.