In 1970, Diehl moved to New York City, encouraged by his sister, who had just graduated from the
Neighborhood Playhouse School of the Theatre. He spent 1971
squatting in
Amsterdam and returned to New York City in 1972. In 1976, he moved to Los Angeles. He had always been interested in drawing and making things, and intended to pursue a career in the visual arts there. Initially, he supported himself in Los Angeles by moving furniture and ''
objet d'art''. Diehl's first significant film role was in the 1981 movie
Stripes. In the 25th Anniversary DVD release of
Stripes, John Laroquette compared the improvisation of
John Candy and Diehl to the improvisation of
Stan Laurel and
Oliver Hardy. In 1983, Diehl appeared in ''
National Lampoon's Vacation'', which
Harold Ramis directed. In 1984, Diehl was cast as Detective Larry Zito in
Miami Vice. Diehl found the role unfulfilling, and decided to leave. On January 9, 1987 — the 57th episode of
Miami Vice — Diehl made his last appearance in a two-part episode, "Down for the Count", in which his character was killed off. Diehl moved into a basement apartment in
Greenwich Village in New York City, and despite a drastic reduction in his income, he declined television roles, and chose, instead, to continue working in film while pursuing a serious stage career. and
Alex Cox's
Walker (1987), which was shot in Nicaragua during the Contra War. In late 1988, Diehl relocated to Los Angeles after he was cast in Sam Shepard's
A Lie of the Mind at the
Mark Taper Forum. He continued to work in theater in New York City, however, and frequently returned to the stage there, most notably for a Shepard play at the Public Theater with Shepard in residence at the Signature, and Mednick's
Joe and Betty, which was produced twice on Theater Row there. In 1997, Diehl reprised his role in
Action at the Public Theater, and in 2005, he worked once again with Padua Playwrights, appearing in two plays in Mednick's
Gary Trilogy. Among others, his theater credits include
Life of Mine, (with
Holly Hunter) at the
Mark Taper Forum,
Samuel Beckett's
Endgame, and
Happy Days, one of three plays which Diehl directed. He has appeared in more than 140 films, including
Joysticks (1983),
Angel (1984),
City Limits (1984),
Madhouse (1990),
The Dark Side of the Moon (1990),
Kickboxer 2 (1991),
Mikey (1992), ''
Mo' Money (1992), Gettysburg (1993), The Client (1994), Stargate (1994), The New Age (1994), Mind Ripper (1995), A Time to Kill (1996), Pearl Harbor (2001), and Road to Nowhere'' (2010). He played
G. Gordon Liddy in
Oliver Stone's
Nixon (1995), the mercenary Cooper in
Jurassic Park III (2001), and in recurring roles on
The Shield, Friday Night Lights,
The West Wing, and
The John Larroquette Show. In 2000, he appeared in
Fail Safe, which aired live on television. Between 2002 and 2004, he portrayed
General Motors'
Harley Earl in a series of television commercials for
Buick. The commercials were directed by
Tony Scott, who had previously directed films including
Top Gun and
Crimson Tide. In 2004,
Wim Wenders cast Diehl as the male lead in
Land of Plenty, a film about post
9/11 American life. Shot on digital video in 16 days, the film centered on Diehl's character, Paul, a troubled Vietnam veteran, and his niece, played by
Michelle Williams. In a
New York Times review of the film,
A.O. Scott wrote that Diehl gave a "wry, cunning performance, allowing glimmers of Paul's intelligence and decency to shine through even in his moments of high self-delusion." A member of the
Actors Studio since 2004, Diehl won the
Los Angeles Times Warren Award in 2012, and in 2014 won the Southampton Film Festival's Lead Actor Award for his role in the short film
Kahea. ==Personal life==