The Korea Media Rating Board forced Kim Jee-woon to recut the film for its theatrical release, objecting to its violent content. Otherwise, the film would have gotten a "Restricted" rating, preventing any sort of release in theaters or on home video.
Director Kim Jee-woon revealed how some Indian producers were interested in the film's remake rights. Since the agreement failed at the negotiation table, he laughed, "They made it anyway." That film was Ek Villain (2014).
Arnold Schwarzenegger was so impressed with this film, he later worked with the director on his movie El último desafío (2013).
This movie marked Choi Min-sik's first major acting role since his self-imposed exile over his protest of the Korean screen quota system. It also reunited Lee Byung-hun with Kim Jee-woon, with whom he had worked in the past on films such as Dalkomhan insaeng (2005).
The international cut did away a lot of sequences the director regarded unnecessary and added all the scenes banned by the Korean censor board, yet it's the Korean cut which runs longer than the international one.