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.

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."

For the seventh year in a row, Congress has failed to pass a defense appropriations bill in time to start the fiscal year. And for the past four years, the Defense Department and other federal agencies have been struggling with the impact of sequestration, which imposed cuts that were never meant to be implemented, but were supposed to prod both parties to come together and reach a budget agreement. The Defense Department has done its best to manage through this prolonged period of budget uncertainty, making painful choices and trade-offs among the size, capabilities and readiness of the joint force.

The nation cannot allow this to become the new normal.

"Iran's continued pursuit of an illicit nuclear program and North Korea's rash intimidation after sinking a South Korean navy ship are but the most recent reminders of the real need for effective U.S. missile defenses," write Under Secretary of Defense for Policy Michele Flournoy and Under Secretary of Defense for Acquisition, Technology and Logistics Ashton Carter.

President Barack Obama announced Monday that he has nominated Dr. Ashton B. Carter to serve as Under Secretary of Defense for Acquisition, Technology and Logistics.

Dr. Ashton B. Carter and Ambassador Robert G. Joseph discuss recommendations stemming from recommendations in final report of the review they co-chaired of the Defense Threat Reduction Agency (DTRA) and other DOD efforts to counter weapons of mass destruction.

A key challenge for the next administration's national security leadership concerns the management of investment in the U.S. national security future. In this paper for the Aspen Strategy Group, Dr. Ashton Carter discusses the challenges of defense budgeting and program selection, and the current mismatch between resources and strategy.

Full text of the trip report from PDP's Track II meetings in Taiwan and the People's Republic of China (PRC).

PDP Co-Director Ashton B. Carter testifies before the Senate Committee on Homeland Security and Governmental Affairs.

PDP Co-Director Ashton B. Carter and the Honorable Robert G. Joseph co-chaired a Review Panel on Future Directions for DTRA Missions and Capabilities to Combat Weapons of Mass Destruction (WMD).