Colonel Frank Cromwell, Air Force Special Operations, had been a friend of O'Neill's. On a joint mission years before, O'Neill had been wounded, and Cromwell, believing that O'Neill was dead, made the decision to save the rest of his team, leaving O'Neill behind to spend four months in an Iraqi prison. They were reunited at the SGC when a Special Forces team was called in during the black hole incident because of a feared alien incursion. In an attempt at reconciliation, Cromwell teamed with O'Neill to break the wormhole connection to P3W-451, but he was drawn into the black hole through the stargate, and was lost.
Portrayed by: Marshall Teague
Episode Reference: A Matter of Time