Petraeus is CIA, retired from the military.
The guy would be Gen. Martin Dempsey, CJCS, who is, coincidentally, in Israel meeting with Ehud Barak, the leftist Israeli Defense Minister who likely will lose his seat in the Kenesset.
CJCS doesn’t have that authority (C&S 101). Only the Natl Command Authority or President would be in his operational command chain. SecDef might also have the authority, but technically the NCA forms the JTFs and is the only one with authority to terminate those commands. Joint Chiefs provide staffing support and are generally used by POTUS to coordinate between higher authority and the CinCs.
The guy would be Gen. Martin Dempsey, CJCS."
Thanks for education, jjotto.