Ted Postol happens to be one of many experts who have grave doubts that such a feat of technological virtuosity, often described as hitting a bullet with a bullet, is possible, or at least sufficiently probable to bet our national security and tens of billions of dollars on. “If you're going to build weapons,” he likes to say, “they ought to work.” And the kill vehicles, by his assessment, most likely will not work. This adds a moral dimension to his outrage: if the government insists on deploying a dysfunctional missile defense system and believing, or at least pretending to believe, that it works, thousands or even hundreds of thousands of people could get killed. Anyone who knows better and doesn't actively work to expose the truth is culpable, Postol believes. As he recently wrote in a characteristically irate letter to President Vest, failure to speak out under these circumstances is morally equivalent to the decision of a structural engineer who knows otherwise to “[tell] the occupants of the burning World Trade Towers, '" Don't worry, the buildings won't collapse.'”