The Resilience of the Electric Power Delivery System in Response to Terrorism and Natural Disasters is the summary of a workshop convened in February 2013 as a follow-up to the release of the National Research Council report Terrorism and the Electric Power Delivery System. That report had been written in 2007 for the Department of Homeland Security, but publication was delayed because of security concerns. While most of the committee's findings were still relevant, many developments affecting vulnerability had occurred in the interval. The 2013 workshop was a discussion of the committee\'s results, what had changed in recent years, and how lessons learned about the grid's resilience to terrorism could be applied to other threats to the grid resulting from natural disasters. The purpose was not to translate the entire report into the present, but to focus on key issues relevant to making the grid sufficiently robust that it could handle inevitable failures without disastrous impact. The workshop focused on five key areas: physical vulnerabilities of the grid; cybersecurity; mitigation and response to outages; community resilience and the provision of critical services; and future technologies and policies that could enhance the resilience of the electric power delivery system. The electric power transmission and distribution system (the grid) is an extraordinarily complex network of wires, transformers, and associated equipment and control software designed to transmit electricity from where it is generated, usually in centralized power plants, to commercial, residential, and industrial users. Because the U.S. infrastructure has become increasingly dependent on electricity, vulnerabilities in the grid have the potential to cascade well beyond whether the lights turn on, impacting among other basic services such as the fueling infrastructure, the economic system, and emergency services. The Resilience of the Electric Power Delivery System in Response to Terrorism and Natural Disasters discusses physical vulnerabilities and the cybersecurity of the grid, ways in which communities respond to widespread outages and how to minimize these impacts, the grid of tomorrow, and how resilience can be encouraged and built into the grid in the future.