Sixteen years after Donald P. Bellisario left NCIS, the show's co-creators, producers, and director have spoken about the conflict that led to his departure. The conflict between Bellisario and Mark Harmon, who plays agent Leroy Jethro Gibbs, caused Bellisario to step away from the show after the fifth season. Despite the conflict, Harmon's dedication to the show and his role as Gibbs has been pivotal in its success, and he has continued to support those around him. Harmon's commitment to NCIS led to the show's survival and continued popularity.