The plot involved a hitman with a conscience who didn’t want to kill a targets wife and son, as a result of him refusing to carry out the hit, he becomes the target of the person who initially hired him. The movie starred a well known Asian/Asian American action star but I’m not sure which one. I’m thinking either Jackie Chan, Chow Yun-fat, or Jet Li. It’s possible it may have been someone else but I do remember that both the protagonist and the antagonist in this film were Asian or Asian American.