The Mouse That Roared (1959)

An impoverished backward nation declares a war on the United States of America, hoping to lose. (imdb)
Cast and Information
Directed By: Jack Arnold
Written By: Stanley Mann, Roger MacDougall
Starring: Peter Sellers, Leo McKern, William Hartnell, Jean Seberg, David Kossoff, Alan Gifford, MacDonald Parke
Country: UK