Gallup has a new poll out about U.S. public opinion on military issues. It reports that only half of Americans believe that the United States “is number one in the world militarily,” while a remarkable 47 percent think “it is only one of several leading military powers.” Needless to say, these 47 percent are mistaken, as the U.S. armed forces far exceed those of any other nation in terms of both spending and strength.

But while some commentators who have remarked on this poll have tied it to the ongoing debate over sequestration and the coming cuts in defense spending, the results seem to say something broader. After all, as Gallup has asked that question over the past twenty years, at least 34 percent in every survey have denied that America has the world’s strongest military. The number may have increased over the past three years, but the misperception it represents is not a new one.

So why do so many Americans believe this? One reason is the habitual tendency of U.S. policy makers to exaggerate threats and dangers around the world, as Micah Zenko and Michael Cohen chronicled in their Foreign Affairs essay “Clear and Present Safety” last year. With leaders constantly stressing how dangerous and threatening the world is, it’s no wonder that the U.S. public believes a number of mistaken things about global affairs—and that many of them involve either overstating threats or understating Washington’s own power. For example, a 2010 CNN poll found that 71 percent of Americans believe that Iran currently has nuclear weapons. A separate CNN poll in 2012 indicated that Americans believe that the threat from Iran is on par with the danger presented by the Soviet Union in the mid-1980s. These latest results from Gallup appear to be part of the same story.