When I began my career in elementary particle physics, the great figures who taught and inspired me had been part of the Manhattan Project generation that developed the atomic bomb. They were proud to have created a “disruptive” technology that ended World War II and deterred a third world war through more than 50 years of tense East-West standoff. They were also proud to have made nuclear power possible. But their understanding of the underlying technology also gave them a deep regard for the awesome, unavoidable risks that came with those technologies.

As Director and Co-Director of the Belfer Center, Ash Carter and Eric Rosenbach have inherited from Graham Allison the world’s No. 1-ranked university think tank. They intend to build on that success by sustaining the Center’s core mission while widening its aperture; enhancing its unique ability to leverage science and technology to meet global challenges; and priming the next generation of leaders in both scholarship and policymaking.

Ash Carter discusses public service, opening the military to transgender troops, and North Korea's latest missile launch with actor Jim Parsons on his SiriusXM radio show "Jim Parsons Is Too Stupid For Politics."

From sharply rising tensions with a nuclear North Korea and decertification of the Iran nuclear deal to China’s growing global assertiveness and the State Department pullback from projecting American values, such as democracy and human rights, around the world, the United States faces urgent national security challenges.

In a panel discussion Monday evening at Harvard Kennedy School (HKS) moderated by MSNBC host Rachel Maddow, former members of President Obama’s cabinet described what they see as a fraying of alliances, a loss of credibility with allies and enemies, a stepping back as a leader on human rights and democracy, and a relinquishment of diplomacy as a critical component of national security.

This report of the International Security Advisory Board (ISAB) offers nineteen recommendations for discouraging a cascade of nuclear weapons states.

Failure to develop a comprehensive contingency plan, such as the one proposed here, and inform the American public, where appropriate, about its particulars will only serve to amplify the devastating impact of any nuclear attack on a U.S. city

Former Clinton administration officials Ashton Carter and William Perry argue that the most effective way to curb the threat from Pyongyang is to destroy its missiles at their test sites

Should the United States allow a country openly hostile to it and armed with nuclear weapons to perfect an intercontinental ballistic missile capable of delivering nuclear weapons to U.S. soil? We believe not. If North Korea persists in its launch preparations, the United States should immediately make clear its intention to strike and destroy the North Korean Taepodong missile before it can be launched.

Dr. Ashton B. Carter testifies before the Senate Committee on Foreign Relations.

A paper by the National Security Advisory Group