Christopher Nolan's nuclear thriller "Oppenheimer" has debuted a tense new trailer.

The movie, based on the Pulitzer Prize-winning book "American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer" by Kai Bird and Martin J. Sherwin, is about atomic bomb creator J. Robert Oppenheimer.

Starring Cillian Murphy as Openheimer, the film focuses on the 1945 Trinity Test in New Mexico, where the world's first nuclear device was detonated successfully.

"You're the man who gave them the power to destroy themselves," Oppenheimer is warned in the trailer. "The world is not prepared."

Matt Damon, Florence Pugh, Emily Blunt, Robert Downey Jr., Kenneth Branagh, David Krumholtz and Josh Peck also star.

Murphy has previously worked with Nolan on "Inception," "Dunkirk" and "The Dark Knight" trilogy.

"Oppenheimer" will be released in theaters on July 21.