After 10 years of war, the vast majority of post-Sept. 11 veterans say the public does not understand the problems faced by those in the military and by their families. The public largely agrees but believes there's nothing unfair about the outsized burden being shouldered by veterans. The findings are part of a broad new study by the Pew Research Center that documents a growing gap between civilians and a military force that has been put under intense strain over the past decade. Less than 1 percent of the U.S. population has been on active military duty at any given time during the past decade. For many Americans, the wars in Iraq and Afghanistan have been seen only in glimpses, in a newspaper or on television. For many veterans, however, the wars have meant incredible strains that have lasted long beyond their deployments. Roughly 44 percent of post-9/11 veterans say their readjustment to civilian life was difficult, according to the Pew study. By contrast, 25 percent of veterans who served in earlier eras said the same. Nearly four in 10 said that they believe they have suffered from post-traumatic stress, regardless of whether they have been formally diagnosed.