Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, and Mr. Petraeus leave a meeting with Iraqi Prime Minister Nouri al-Maliki in Baghdad during a six-day tour in 2008. (Associated Press)

Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, and Mr. Petraeus leave a meeting with Iraqi Prime Minister Nouri al-Maliki in Baghdad during a six-day tour in 2008. (Associated Press)