It’s a 10-minute walk from my office to where everything changed forever. A sculpture by Henry Moore marks the site at the University of Chicago where, on December 2, 1942, physicists achieved the world’s first self-sustaining nuclear reaction. Yet, for most people in the world, their introduction to nuclear physics would come abruptly less than three years later, when the United States dropped the atomic bombs on Hiroshima and Nagasaki. A group of Manhattan Project scientists had warned that this was a dangerous and ruthless way to usher in the nuclear era—a decision that would inevitably prompt a race among other nations to obtain this ultimate weapon. Their warnings went unheeded. But rather than retreat in despair to their laboratories, in December 1945 they began publishing the Bulletin of the Atomic Scientists. They believed the stakes for the human race were too high to entrust this debate to a handful of scientists, military leaders, and government officials. (For them, “publish or perish” took on a literal meaning.) They felt an obligation to make their knowledge accessible to the general public and to address the consequences of what they had themselves created. Reflecting on the Bulletin’s mission, Eugene Rabinowitch, the magazine’s cofounder, aptly described it as “part of the conspiracy to preserve our civilization by scaring men into rationality.” Regrettably, six decades after the Bulletin’s founding, fear remains in abundance, while rationality is in short supply. As such, the Bulletin’s sixtieth anniversary is a bittersweet celebration. On the one hand, we take extraordinary pride in what this publication has accomplished in alerting the public to the dangers of nuclear, biological, and chemical weapons, as well as highlighting important political issues such as government secrecy and human rights. On the other hand, we recognize that in a world still bristling with more than 20,000 nuclear warheads and where terrorist groups scour the globe for fissile materials, our mission remains far from complete. As Joseph Cirincione of the Carnegie Endowment for International Peace observes in this issue, we had a window of opportunity 60 years ago to push for the international control of atomic energy (p. 42). Instead, we chose a different path, leading us down the dead end of a costly and dangerous arms race. But, whereas our choices six decades ago were circumscribed by the looming threat of Soviet power, our current political climate allows for considerably more freedom of movement. Many of the programs to safeguard fissile materials, reduce nuclear stockpiles, and prevent nuclear proliferation are already in place. As Cirincione notes, “All that’s lacking is real action and real money.” Hopefully, this opportunity will not be allowed to pass, as it did 60 years ago. It’s rare that the world gets a second chance. Mark Strauss EXECUTIVE DIRECTOR Kennette Benedict EDITOR Mark Strauss MANAGING EDITOR Catherine Auer ASSISTANT EDITOR Jonas Siegel ASSISTANT EDITOR Josh Schollmeyer ART DIRECTOR Joy Olivia Miller WEB DESIGNER Jim Grisius DEVELOPMENT& MARKETING DIRECTOR Lisa Miller ASSOCIATE DIRECTOR E. Ruth White EXECUTIVE ASSISTANT Anthony McGeath