Vietnam

During the war, young men often tried to join the National Guard to avoid being sent overseas. But that war changed the nature of the guard — paving the way for today's deployments abroad.

The planes used to spray Agent Orange in Vietnam weren't retired from service — they were used by reservists in the U.S. for more than a decade after the war, exposing the crews to harmful chemicals.

Demand for rhino horn, used in traditional Chinese medicine, is fueling a slaughter of the animals in Africa. In Vietnam, the sought-after commodity is fetching prices as high as $1,400 an ounce, or about the price of gold. There, some believe ground horn can cure everything from hangovers to cancer.