Advances in technology often concur with times of war—the nuclear bomb is perhaps the most iconic example. The then-new knowledge of nuclear physics and the fear that the Nazis might develop a weapon pushed some of the greatest minds in physics and chemistry to solve one of the most complex technical problems of the day. Their success ushered in a new age; the rules of warfare had to change when a reckless act might end human civilization. In this eBook, The Changing Face of War, we examine the technologies being developed or adapted for war and defense—and what these innovations mean for the way nations (and non-state antagonists) conduct military or security operations. From drones to computer systems to biological and chemical weapons, each advance demands a re-thinking of where the vulnerabilities lie and how severe any collateral damage would be. In Section 1, “Death from the Sky: Drones,” author Larry Greenemeier looks at the length and breadth of drone usage while John Villasenor tackles the questions raised about national security and privacy. Vulnerability takes on new meaning in Section 3, “The Cyberwars,” as David Nicol illustrates how the Stuxnet worm put a serious dent in Iran's program to enrich uranium in “Hacking the Lights Out.” Sections 6 and 7, “Nuclear Weapons” and “Star Wars: Attack from Orbit,” respectively, delve more closely into the consequences of collateral damage. In her article "Space War," Theresa Hitchens outlines the downside of nations taking the “high ground” in space, where even testing such weapons could create so much wreckage as to damage or destroy any craft in Earth’s orbit. But these questions aren’t new. We have powers to destroy that would have awed the ancient conquerors. With luck, we will keep that power under control.