Book excerpt: U.S. security does not require nearly 1,600 nuclear weapons deployed on a triad of systems—bombers, land-based intercontinental ballistic missiles (ICBMs), and submarine-launched ballistic missiles (SLBMs)—to deliver them. A new paper from Benjamin H. Friedman, Christopher A. Preble and Matt Fay encourages abandonment of the triad and skepticism about the received wisdom justifying U.S. nuclear weapons’ policies. The authors suggest that shifting to a submarine-based monad would serve U.S. deterrent needs and eventually save taxpayers roughly $20 billion a year.