While he agreed with the military's involvement in the region, Rush's participation in this conflict can be seen as a defining event for the director who later explained: There's a recurring theme that I keep getting attracted to in film.

Magic, king, country, mother, God, all those burning truths we got from our early bathroom training from bumper stickers and from crocheted pillow cases.

[citation needed]After his military-related work, Rush opened a production company to produce commercials and industrial films.

Rush directed a car racing film for American International Pictures, Thunder Alley (1967) starring Fabian Forte and Annette Funicello.

Rush was hired to direct One Flew Over the Cuckoo's Nest (1975) after its original director Miloš Forman was placed under increasing censorship and StB surveillance by the normalization-era Communist Party government of Czechoslovakia.

"[9] The film, which took Rush nine years to put together,[citation needed] was a slapstick comedy, a thriller, a romance, an action-adventure, and a commentary on America's dismissal of veterans, as well as a deconstruction of Hollywood cinema.

The film also features Rush's typical protagonist, an emotionally traumatized male who has escaped the traditional frameworks of society only to find his new world (biker gangs in Hells Angels on Wheels, hippies in Psych-Out) corrupted by the same influences.

[10] Rush originally wanted to direct the horror comedy Love at First Bite (1979) as his first film after The Stunt Man, but was replaced by Stan Dragoti.

[12] This allowed the studio to cast Mel Gibson and Robert Downey, Jr. and turn the film into a success, grossing nearly double its budget.

As Kenneth Turan of The Los Angeles Times wrote, Rush's career seems to be "followed by the kind of miserable luck that never seems to afflict the untalented.

On April 8, 2021, Rush died a week shy of his 92nd birthday at his Los Angeles home after long-term health problems.