The United States and Vietnam established diplomatic relations in 1995, 20 years after the end of the Vietnam War. Rebuilding trust between former enemies is not an easy task, because each side must rethink how it perceives the other and also offer some concrete signs of goodwill. What does the U.S. government want from the Vietnamese and what is it offering in return?

Last week William Cohen became the first U. S. Secretary of Defense to visit Vietnam since the end of the war in 1975. Cohen's highest priority was resolving the cases of U.S. soldiers missing in action (MIA). Other proposed cooperative projects include removing old land mines, improving Vietnam's flood control, and studies of tropical medicine and the environment.

The Vietnam War claimed the lives of 58,000 U.S. soldiers and approximately 3 million Vietnamese from both sides of the civil war. Approximately 2,000 American servicemen are still listed as missing in action, and the U.S. military establishment is working to find and identify their remains to bring home for burial. At the close of Cohen's visit, the Pentagon announced that the remains of two MIAs had been found and identified, and are being returned to their families.

• Read about Cohen's trip in the CNN article: "Cohen ends Vietnam trip; MIAs' remains sent to families."

Once remains are found, the task of identifying the soldier begins. New high-tech methods are making the job easier. Just last fall the U.S. Army finally identified 9 of 13 bodies from the Knife 13 helicopter crash on a Cambodian island 25 years ago.

One of the leading identification methods is comparing a soldier's dental X rays to actual remains. New databases have improved the results of this technique. Another major technique is DNA testing. Since the army does not have on record DNA samples for soldiers who fought in the Vietnam and Korean wars, investigators compare DNA from remains to DNA from blood samples of close relatives.

• Read more about the identification technologies in the CNN article: "IT fills in puzzle of Korean, Vietnam War MIAs."

The Tomb of the Unknowns at Arlington National Cemetery contains the remains of unknown soldiers from World Wars I and II and the Korean War. Until 1998 there were also remains of a soldier from the Vietnam War, but DNA testing enabled identification of the soldier, whose remains were returned to his family. A decision was made to leave the Vietnam Unknown Crypt empty.

• Read more about the identification process at the Arlington National Cemetery's Web section on The Vietnam Unknown Controversy.

Learn about the Problem

Investigators use a technique called "DNA fingerprinting" to compare DNA fragments in order to identify individuals. Perform a simulated identification in the Biology Gateways activity: DNA Fingerprinting.

Think about the Problem

• What prevents DNA fingerprinting from being an effective technique for identifying the remains of a soldier from the Vietnam or Korean War?
  
  
• How can DNA fingerprinting be used to identify a soldier's remains in future military conflicts?
  
  
• What other applications of DNA fingerprinting can you list?

For the Teacher: Extending the Problem

• Students who want to learn more about how the U.S. military identifies the remains of soldiers can visit the site of the U.S. Army Central Identification Laboratory.
  
  
• DNA fingerprinting is also used in forensic work to identify suspects in certain crimes. Students can read more about this in NOVA Online's Killer's Trail.
  
  
• In 1998 an article in Nature magazine published results of a study that used DNA fingerprinting to support the old, unproven claim that Thomas Jefferson fathered illegitimate children with his slave Sally Hemings. Students can read more about the case in the article "Jefferson's secret life."
  
  
• Today's high school students may know more myth than fact about Vietnam. They can learn about the country at the following sites:
  • Vietnam Tourism
  • The World Factbook 1999: Vietnam
  • Vietnam Culture and Information