Hayden made several subsequent well-publicized visits to North Vietnam as well as Cambodia during America's involvement in the Vietnam War, which had expanded under President Richard M. Nixon to include the adjoining nations of Laos and Cambodia, although he did not accompany his future wife, actress Jane Fonda, on her especially controversial trip to Hanoi in the spring of 1972. The next year he married Fonda and they had one child, Troy Garity, born on July 7, 1973. In 1974, he appeared in a brief scene as an ER doctor in the film "Death Wish". In the same year, while the Vietnam War was still ongoing, the documentary film "Introduction to the Enemy", a collaboration by Fonda, Hayden, Haskell Wexler and others, was released. It depicts their travels through North and South Vietnam in spring 1974.