Most African countries are poorly positioned to deal with unanticipated shocks to the global food system. To mitigate vulnerabilities to this systemic risk, a new perspective on food security is needed that both supports diverse trade relationships for staple foods and promotes some degree of self sufficiency in domestic food production in African countries. Here we use a network-based shock propagation model to explore the sensitivity of African countries to short-term production shocks in the global food system. We examine the global cereals trade network for two periods, 1996-2000 and 2006-2010. Our results reveal two trends in African food status: an intensifying dependence on imported cereals complemented by a decline in intra-African trade. We find that maintaining stable intra-African trade links is a critical and effective strategy for absorbing and mitigating food-supply disruptions. Although intra-African trade represents 5.4% and 4.1% of African trade in the 1996-2000 and 2006-2010 time periods respectively, stabilizing intra-African trade links reduces individual African countries exposure to supply shocks by 26% and 20% and to consumption shocks by 22% and 14%, respectively.