We’ve all heard of post-traumatic stress disorder, PTSD. But what exactly is it? The experience of trauma is, unfortunately, all to common even in these relatively safe and peaceful United States. Automobile accidents, violence, abuse, untimely death of a loved one—all can be traumatic.

What distinguishes PTSD from other trauma is the lingering, intrusive nature of it. It seems to take on a life of its own.

Flashbacks and nightmares and a triggering sight or sound or smell can plunge the individual back into a terrible and terrifying re-experiencing of the earlier trauma. The traumatized soldier can shut down and withdraw or become hyper-vigilant and over responsive. The stereotype of the traumatized combat veteran includes a person with a hair-trigger temper, easily over-stimulated and highly reactive to his environment.

But veterans also come home, even from a broader “theater of war,” with more subtle symptoms that include avoidance and numbing. For these soldiers, that suit of emotional armor was essential in protecting them from the intense emotions stirred up by the threat to life and presence of death. Once home, it becomes a severe and heavy handicap. When you can’t feel pain, you also can’t feel love and pleasure.

Today’s soldiers return from overseas duty to a relatively warm welcome. We may object to the war—but embrace the soldier. In my experience, there was no “Welcome Home” coming back from Vietnam. The anti-war movement was raging, and very few of us were advertising our military service. We felt out of synch with our peers, deeply distrustful, and profoundly private about our war experience. Many of us felt ashamed of our participation in a cause we didn’t believe in. As a graduate student in a university setting, nobody wanted to hear—or would believe—that I’d spent a year in Vietnam. It was odd and disorienting.

While this kind of shut down and withdrawal doesn’t meet the criteria for a true PTSD, it was, for hundreds of thousands of non-combat veterans, the legacy of Vietnam.

In 1995, Jonathan Shay in his ground-breaking book, Achilles in Vietnam, wrote persuasively that for those returning from combat with PTSD, there would be no such thing as a “return to normal.” To be exposed to the horrors of war is to be scarred for life. Some degree of recovery is all we can hope for, Shay said.

Fortunately, there are encouraging newer PTSD treatment modalities that have been developing since then. The response time to returning vets has accelerated and follow-up programs and treatment groups have multiplied.

Some of today’s vets object to the stigmatizing that comes from coupling the “D” (Disorder) with the PTS. They argue that it’s not a disorder; it’s a predictable and understandable reaction to an extremely unhealthy situation (the violence of war).

I can appreciate their concern. The Pentagon, in response to the thousands of traumatized soldiers returning from Iraq and Afghanistan, tried to rewrite the PTSD criteria to limit eligibility for benefits. In a show of solidarity, veterans’ organizations and other supporters registered sufficient outrage to force the Pentagon to reconsider.

That the government would make every resource available to support returning soldiers—medically, psychologically, and financially—is simply the right thing to do.