One of the tragedies of the war was the physical effects of the widely used defoliate Agent Orange. When in long-term contact with humans, it creates all kinds of neurological disorders. One of my best friends has facial tics from Agent Orange exposure. Why did the US government deny the harmful effects of this chemical on its troops for so long?
This is a very sensitive topic. Now we know the harmful effect of Agent Orange, but in the past it was contested. There are several reasons for this fact.
First, the government stated that there were no long term effects of Agent Orange. This fact alone made the government reticent of taking back their statements. Admitting a mistake is not easy to do.
Second, it is difficult from a scientific point of view prove correlation. In other words, many things happen in war, and so to say that Agent Orange was the problem of many veterans is not easy to prove.
Finally, the legal ramification were huge. By 1993, the Department of Veterans Affairs only compensated less than 500 people, when nearly 40,000 veterans were exposed to Agent Orange. This costs, therefore, would be great, and the legal course of action would be as expensive.