The Pentagon fired a senior Air Force general over his alleged “unprofessional relationship” with a female lieutenant colonel. Lt. Gen. John Hesterman submitted his retirement papers Thursday from his position as Air Force assistant vice-chief of staff, after an investigation found emails exchanged five years ago “constituted an unprofessional relationship,” according to an Air Force statement. However, the investigation didn’t find any other misconduct. The three-star general was previously the head of Air Force Central Command, in which he directed airstrikes against ISIS fighters in Iraq and Syria. The investigation began last summer when an inspector general received an anonymous tip that Hesterman had engaged in an inappropriate relationship.