There is a military proverb that first reports from the battlefield are always wrong. Last week's reporting from Fort Hood should be taken with that caveat, especially to the extent that we blame the shooter's short Iraq tour for his violent rampage. We know far too little about the shooter, victims and situation to conclude that military service or combat stress caused the carnage at Fort Hood.

It would be enough for these stories to leap to conclusions about one particular shooting. Unfortunately, such reporting (in this case and that of the Navy Yard shooting last September) contributes to a deeply ingrained (and factually false) narrative about veterans that has become a part of the American psyche. This "Rambo narrative" — the idea that veterans are deranged killers suffering from post-traumatic stress, ready to explode in the workplace or at home — did lasting harm to the Vietnam generation of veterans. It persists today, and is only inflamed by reporting like that on the Fort Hood shooting.

In a 2012 report on veterans employment, my colleagues surveyed nearly 70 companies from all sectors on questions of barriers to veterans in the workforce. A majority of companies surveyed said that "negative stereotypes," including but not limited to perceptions of pervasive post-traumatic stress, were a major factor in decisions not to hire veterans. One respondent said that "I've heard about some veterans coming back and going on rampages. I've never had this happen to me personally, but I always wonder if it is a possibility." Others spoke about how media reporting suggested that "all vets have PTSD," even though the data suggest that only a small minority do, and that these concerns may be unfounded or overblown.

It is true that many Iraq veterans — RAND's landmark study suggests approximately one in five — come home with symptoms of post-traumatic stress. It is also true, as shown by the Washington Post's comprehensive survey of post-9/11 veterans, that many struggle with the transition home. Many of us feel ambivalent about our wars and alienated from society upon coming home. Large numbers of Iraq veterans also struggle to find a place in civilian society, whether in the workforce or elsewhere.

This may be hard to believe in a country that publicly venerates its returning veterans as heroes whenever given the chance with standing ovations at baseball games, applause on airplanes, "I Support Our Troops" bumper stickers, flag-waving Budweiser commercials, and a sea of goodwill from charitable organizations. Don't be confused, though: Those gestures, while doubtlessly heartfelt, don't do very much to bridge the yawning divide between the military and civilian worlds in an age when vast swaths of the country simply don't know anyone who serves. They also don't mean that those doing the applauding actually want to know what troops went through in Iraq and Afghanistan — or are willing to avoid jumping to the conclusion that an unhinged soldier must have been unhinged because he was a veteran of our two long wars.

Left unchallenged, the potential popular conception of the veteran as a loose cannon can do lasting damage to the community of post-9/11 veterans who are coming home from Afghanistan and Iraq. The vast majority of Iraq veterans (including those with post-traumatic stress) come home, leave the service without incident, and reintegrate into their communities. This transition is not always easy, and is often made more difficult by misperceptions within civil society about military service and combat stress.

The most pernicious effect of overreporting the Fort Hood shooting may be to make transition harder for the millions of Iraq and Afghanistan veterans who will now encounter a public led to believe that all post-9/11 veterans are powder kegs.

The shooting at Fort Hood was a tragedy. I grieve for its victims, and desperately want to understand more about what caused this soldier to take the lives of his comrades. But we must not let this incident do more damage to an entire generation of veterans by contributing to the erroneous impression that we are all damaged by our service, unfit for society, and ready to blow at any minute.

Phillip Carter is a fellow at the Center for a New American Security. He served in 2009 as the deputy assistant secretary of defense for detainee policy. He wrote this article for Foreign Policy.