As details related to allegations of marital infidelity that led to the resignation of CIA director and former Army Gen. David H. Petraeus unfolded, the Defense Department announced that the chief military commander in Afghanistan has become the subject of a related probe. On Nov. 11, Defense Secretary Leon E. Panetta told the chairmen of the House and Senate armed services committees that Marine Corps Gen. John R. Allen, the commander of the International Security Assistance Force (ISAF) in Afghanistan, has become the subject of an investigation by the Pentagon inspector general. Allen will continue to serve as ISAF commander pending the outcome of the investigation. Petraeus resigned as CIA chief after the FBI discovered evidence that he was in an extramarital relationship with Paula Broadwell, a West Point graduate who wrote a biography of him. According to media reports, the FBI learned of the relationship between Petraeus and Broadwell while investigating allegations that Broadwell had been sending threatening email communications to Jill Kelley, an unpaid volunteer at U.S. Central Command Headquarters at MacDill Air Force Base, Fla. The IG probe will focus upon the thousands of pages of emails Allen and Kelly reportedly have exchanged with one another. Allen publicly has denied any wrongdoing. Meanwhile, Allen’s nomination to succeed Navy Adm. James G. Stavridis as commander of U.S. European Command and the supreme allied commander of NATO forces in Europe has been placed on hold, pending the outcome of the IG probe. The nomination of Gen. Joseph F. Dunford Jr., to succeed Allen at ISAF is also in limbo until the matter is resolved.