From Think Progress:
During the Iraq war, the Central Command (CENTCOM) head — who leads U.S. operations in the entire Middle East region — and the Multinational Force Commander (MNF) have regularly testified together about the course of the war in Iraq.
…snip…
In January, President Bush replaced Abizaid and Casey, who were “surge” skeptics, with Adm. William Fallon and Gen. David Petraeus. This week, Petraeus — in the first public hearings since taking on his new role — delivered his Iraq assessment to great media fanfare. But where was his boss, Admiral Fallon? Inter-Press Service suggests animosity between the two might be one reason for Fallon’s absence:Fallon told Petraeus [in March] that he considered him to be “an ass-kissing little chickensh*t” and added, “I hate people like that”, the sources say. That remark reportedly came after Petraeus began the meeting by making remarks that Fallon interpreted as trying to ingratiate himself with a superior.