Is it true that Natalie Portman changed her last name from herslag to portman because she did not want to get drafted into the isreali military?

No, that claim is not true. Natalie Portman was born Neta-Lee Hershlag in Israel and adopted the stage name Portman, which is her grandmother's maiden name, early in her acting career. The decision to use a different name was not related to avoiding military service; rather, it was a common practice in the entertainment industry. Additionally, Portman has publicly expressed her support for Israel and its military.