The Belmont Club has a very clear explanation of what is going on in Fallujah and Ramadi. Be sure to follow his links, especially to The Adventures of Chester and his links to maps, etc. It is being said that the battle will start immediately after the election.
"Fallujah watchers will have noticed that the Marines are closing out a last round of negotiations for surrender while they have been progressively shutting down insurgent checkpoints within the city by hitting them with smart munitions. My own speculation is that the negotiations were launched, not in the expectation of getting Zarqawi to lay down his arms, but in order to negotiate a separate peace with the different factions in town. The impending assault has been used as a negotiating lever to create gaps in the enemy ranks. This process is calculated to blind the enemy by shutting down his pickets and poison his intelligence channels -- not to mention introducing mutual suspicion and internecine fighting.