The arc of innovation has reached an inflection point: technological change now threatens to overwhelm us. Discovery is unstoppable, but it must be shaped for good. We ourselves—not just market forces—must manage it.

“Honey bots” that counter malicious bots. An app called Sanity Check. Cyber Security Bonds. And technology that breaks the grip of online echo chambers. Those are just some of the ideas that college students from around the country presented Thursday in Cambridge as part of the Defending Digital Democracy Project’s first-ever Information Operations Technical and Policy Hack-a-thon.

In February, the Pentagon released a new Nuclear Posture Review (NPR), a comprehensive overview of the nation’s nuclear forces, their disposition, and plans for the future. Here, Belfer Center experts share their assessments of this NPR and the future of America’s nuclear capabilities.

Nineteen years ago, I was in Ukraine when the last nuclear warheads, orphaned during the Soviet Union’s breakup, rolled out of the country. As an assistant secretary of Defense at the time, I had worked with Washington colleagues and foreign counterparts to eliminate those nuclear weapons and thus one danger at the dawn of the post-Cold War world. Together — with bipartisan support in Congress led by Sens. Sam Nunn, a Democrat, and Richard Lugar, a Republican — we succeeded.

Today, the Iran deal provides the opportunity to address an even greater nuclear threat. Congress should support it because, once implemented, the deal will remove a critical source of risk and uncertainty in a vitally important but tumultuous region.

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.