While emotions have shifted and reasons have changed, Cote de Pablo has consistently pointed to the quality of the writing on "NCIS" to explain her abrupt departure from the series.
"Unfortunately, because of political things and scripts not being good enough, I chose not to [return to 'NCIS']," she told Hello! in 2016. In a 2013 interview with TV Guide, as archived by CBS News, she said it was not an easy decision or one she had planned. She was, however, determined to bring about a proper resolution to the romance between Ziva and Anthony DiNozzo (Michael Weatherly).
De Pablo had major issues with how the writers planned to continue Ziva's arc, which encouraged her to depart "NCIS." "They were going to send [Ziva] back to Israel and make her an unfortunate, miserable woman. I didn't think it was fair. I told them until someone can write something really fantastic for Ziva I won't come back," she said.
While Ziva is initially killed off in an offscreen explosion during Season 11, viewers later learn she's alive. Her presence factors into Anthony's Season 13 exit; he leaves NCIS to care for the daughter she secretly gave birth to while on the run. Ziva returns during a Season 16 cliffhanger, alive and well. She is a recurring character during Season 17, appearing in four episodes before ultimately returning to Tony and her daughter. By then, the conflict between the actress and the show seemed to have melted away. Hopefully, the tension between de Pablo and McCallum also came to a happy resolution.