Robert Davi
From Halopedia, the Halo wiki
Summary
Robert Davi is an American actor. He was born on June 26, 1954 in Queens, New York.
He is well known for his rugged features and impressive stature, so he tends to play villans in his productions. His screen credits include the James Bond film Licence To Kill, as well as Die Hard, and for his role in Stargate: Atlantis.
He voiced the SpecOps Elite Commander "Rtas 'Vadumee" in Halo 2. It is likely that he will return in the same role in Halo 3.