In the spring of 1965, we became part of the great American conventional army dispatched to Vietnam. Pound for pound our airmen, marines, sailors and soldiers were collectively the finest warriors we had ever sent to war. In the beginning, we were highly trained regular volunteers, who had long been indoctrinated to kill a "Commy for Mommy."

But we were trained to fight the Soviet Union. American tactics and equipment were designed to engage a Communist enemy on a European battlefield, not an Asian opponent in the jungle. The training and mindset of our generals and admirals were to fight air, land and sea battles like those that brought us victory in World War II.

There was another problem we had to face. Our Vietnamese opponent refused to be sucked into a war of attrition or to fight an American style war. Over the centuries, the Vietnamese defeated the Chinese, Japanese and the French, not by fighting by conventional rules, but by following the strategic and tactical doctrine of Sun Tzu, written two and a half thousand years before: "enemy attacks, we retreat; enemy digs in, we harass; enemy exhausted, we attack; enemy retreats, we pursue."

For eight years, our powerful US war machine mostly attacked shadows and mainly bombed an invisible enemy. We were seldom able to lock our opponent into the much sought-after classical big battle, where we could bring to bear our overwhelming firepower and technological advantage over this Third World foe. Our enemy fought battle for battle mainly on his terms. He acted; we reacted. When the fight was over he danced away to fight another day, almost always leaving the ground bloody from American casualties. He took his lumps too, but they weren't shown on the Vietnamese nightly TV news.