The war had been over for 9 years when this song came out. It's about the lasting mental effects (post traumatic stress) that result from combat. At this time Americans were beginning to look at Vietnam Veterans a different way. They began to understand that just because the war was unpopular does not mean that you shun the veterans.

I feel that one thing that made post traumatic stress worse in many cases was the tendency of many Americans to neglect, ignore and sometimes even abuse those who fought. Thankfully, that attitude has really changed in the past 30 years. But it came too late for some Vietnam Veterans.
(From members.tripod.com)