Power is not always angelic. When the power to do something exists, it often gathers like a storm, ready to be unleashed. Power is also agnostic; it can be used for evil as well as for good. One thing is for certain. Without concentrations of power, not very much, for better or for worse, would ever get done. Consolidated power can tilt towards moderation or in the opposite direction. Governments that are locked and loaded are as likely to be embarrassingly trigger-happy as they are to act wisely. Telling examples include the United States’ retaliatory invasion of Afghanistan in 2001,...