Between 2014 and 2023, the United States expects to spend $355 billion to modernize its nuclear arsenal. In subsequent decades, even higher expenditures are envisioned. But Washington is far from alone in modernizing its nuclear weapons. According to researchers from the Federation of American Scientists, "all the nuclear-armed states have ambitious nuclear weapon modernization programs … that appear intended to prolong the nuclear era indefinitely." Disarmament advocates believe such modernizations are fundamentally at odds with the goal of eliminating nuclear weapons—while weapon states argue that, as long as nuclear weapons exist, arsenals must be modernized in order to keep them safe, secure, and effective. In a world where complete disarmament is nearly every nation's stated goal but disarmament seems by no means imminent, how should nuclear-armed countries approach the maintenance and modernization of their arsenals?