The movie promotes standing up for what you believe in and making sure your voice is heard. It also stresses the importance of honesty in romantic relationships.
The opening sequence takes place in Vietnam, and there are a couple of close calls, but only one character is actually shot and injured. Mickey discusses some of his fellow soldiers who've died in battle, and Dalton hits a pacifist who was kissing his fiancee. Police roughly arrest protesters, and two friends find out that another friend in Vietnam has died.
Two love scenes show bare-chested men and women who are either wearing a bra or have a sheet or blanket covering them up. A couple of passionate kisses -- one that's scandalous because it's obvious the young woman doesn't believe in monogamy (she had just gotten engaged to someone else).
A few uses of "s--t, " "a--hole," and "bitch."
College-age students and soldiers smoke marijuana (a few times) and get drunk and/or drink heavily -- in keeping with the reputation for open drug use among young people in the '60s.