More than 3 million people (including 58,000 Americans) were killed in the Vietnam War; more than half were Vietnamese civilians. By 1969, at the peak of U.S. involvement in the war, more than 500,000 U.S. military personnel were involved in the Vietnam conflict. Growing opposition to the war in the United States led to bitter divisions among Americans, both before and after President Richard Nixon ordered the withdrawal of U.S. forces in 1973.
Physical dependence refers to a state resulting from chronic use of a drug that has produced tolerance and where negative physical symptoms of withdrawal result from abrupt discontinuation or dosage reduction.hysical dependence can develop from low-dose therapeutic use of certain medications such as benzodiazepines, opioids, antiepileptics and antidepressants, as well as misuse of recreational drugs such as alcohol, opioids, and benzodiazepines.
Mental/psychological dependence means somebody can't feel comfortable/relaxed anymore without the drug. This mechanism has nothing to do with the body, but with feelings of fear, pain, shame, guilt, loneliness and so on. The drug is used to forget problems which should be solved.