Why an admiral?

There has been a quiet discussion going on in the blogosphere as to why a navy admiral has been appointed to head up the forces fighting two ground wars in Iraq and Afghanistan. One theory: we're about to have still a third war with Iran that will be waged from the air and the sea. Unfortunately, this sounds plausible to me. Here's Mimikatz's take at the Next Hurrah:

Amid the extensive reorganization of Bush's National Security team one appointment stands out: Admiral William J. "Fox" Fallon, currently head of the Pacific Command, will replace retiring General John Abizaid as head of the Central Command. While several of Bush's recent appointments have met with some favor, such as the appointments of General David Petraeus to replace General Casey as head of the "Coalition" forces, Zalmay Khalilizad as UN Representative and Ryan Crocker as Ambassador to Iraq, all praised by Juan Cole as serious and qualified professionals, why would he appoint a Navy Admiral to head a theater that is traditionally the province of the Army and Marines and where we are currently engaged in two ground wars? Is it because Admiral Fallon's background in naval aviation would be more relevant in an upcoming conflict that is likely to be an air-and-sea war? After all, Iran is under Centcom too.

With two more years of Bush destroying us, will we even have a country left?