For American defense professionals, the 1990s now seem like a distant dream. The United States was fresh off a stunning military victory over Iraqi dictator Saddam Hussein’s forces in Kuwait. The Soviet Union, long Washington’s bête noire, had crumbled. The American economy was robust, churning out important technological innovations one after another. In these halcyon times, U.S. military leaders and defense officials predicted that they would master what they called the “revolution in military affairs,” thereby attaining battlefield superiority over every possible enemy. Since the U.S. would be able to impose its will on opponents, there was little need to consider how enemies thought or what they intended to do.

A decade later, however, the slogging, bloody counterinsurgency campaigns in Iraq and Afghanistan showed that technology could not solve every security problem. Ideas and concepts, not to mention will and perseverance, mattered greatly. Then, just as the U.S. extricated itself from the counterinsurgency morass, the American economy tanked, taking the defense budget with it. The dreams of the 1990s had given way to nightmares. ...