By: Mark Leon Goldberg on October 29, 2014 Jessica Tuchman Mathews is stepping down as the head of the Carnegie Endowment for International Peace after 18 years at the helm. She will be replaced by William Burns, the former deputy Secretary of State for Hillary Clinton and John Kerry. I don’t know Ms. Mathews personally, but her writing has deeply influenced how I understand the world. Two Foreign Affairs articles in particular, “Redefining Security” in 1989 and “Powershift” in 1997, presented pioneering ideas that shaped the foreign policy debate during a rapidly evolving period in international relations. In “Redefining Security” she prophetically argued that issues like climate change and global health will become priority security concerns–and that our very understanding of “security” needs to be expanded to include issues that affect populations, not just states. Today this is called “human security” — and it is commonly accepted–but at the time the notion was heretical to the international relations establishment. In “Powershift,” she argued that non-state actors like NGOs will become increasingly relevant arbiters of security. This was also heretical at the time because most international relations theorists were still arguing that “security” was firmly in the realm of state power, and state power alone. Mathews also has a very remarkable personal story, which she told me a few months ago for a podcast episode. She discusses the influence of her mother, the Pulitzer prize winning historian Barbara Tuchman, why she opted to get a Phd in molecular biology, and how she transitioned from the hard sciences to a career in foreign policy. She also discusses the genesis of those two influential articles.