As a result of the uprising that followed, Fallujah essentially fell under the control of the resistance, which has used the city as a base of operations. Likewise, Samarra and Ramadi also became cities under questionable Coalition control. Moqtada al-Sadr's forces licked their wounds, learned their lessons, and trained and recruited further.
This month, however, has the very real potential of turning into another April-like event. The delicate nature of the confrontation in Najaf around its holy sites means that any final battle will have to be waged primarily by Iraqi troops. These troops are highly undependable, as they include many who may not be willing to fight fellow Iraqis defending their country's most holy landmark.
Recently, in Hilla, Moqtada al-Sadr's supporters overran approximately 200 Iraqi national guard troops who would not fight them, taking their weapons. Something like this occurring during the "final battle" with Sadr could be the undoing of the Allawi government in all ways that matter, so Allawi may be forced to use more loyal / anti-Shi'ite Kurdish troops against the Shi'ites, just as they were used against the Sunni in Fallujah. This could be an incredibly divisive thing to do, as it could lead to a wider civil war.
Articles are reporting that thousands of protesters from southern Iraq have converged on Najaf and have joined Sadr in the defence of the Imam Ali Mosque. It also seems likely that foriegn aid and fighters are likely to arrive from numerous locations around the Arab world. It is, therefore, entirely possible that the entire Iraqi army couldn't defeat Moqtada al-Sadr at this point -- despite the pummelling they've had over the last week, Sadr's forces in Najaf are almost certainly stronger than they were when the confrontation began last week.
If the Iraqi army tried attacking Sadr's forces and failed, it could lead to a situation where U.S. forces would get drawn into the fight anyway, no matter how bad the consequences could become. Unrest if Najaf is attacked would almost certainly spread across southern Iraq and in Baghdad as a result -- most likely to a greater degree than they did during the past week.
The big wildcard, however, is what might happen in Sunni territory. A story came over the wire today that is quite disconcerting. Apparently, there are plans to disband the Fallujah Brigade", the all-Iraqi guardians of Fallujah, led by former Saddam loyalists. The Fallujah Brigade is ultimately loyal to Iraqis, however, not the coalition forces, and will not disband so easily. After all, they control Fallujah, and pride themselves on their autonomy. It appears likely that a wider confrontation is planned in Fallujah. The ground is literally being laid for another April-like scenario if the Coalition doesn't play their cards right.
Sunni and Shi'a resistance is far more united now than it has ever been. A good example was seen today, when a large aid convoy arrived in Najaf from Fallujah, escorted by Sunni clerics and clan elders. They met with local clergymen in Najaf, and expressed solidarity with the city and its resistance.
If Sunnis and Shi'ites unite during a time of shared opposition, watch out. It's questionable whether even Sistani could calm such a widescale uprising. The result could be the illegitamizing of Allawi, widescale opposition against both the U.S. and British forces, defections from the Iraqi military and police, and anti-Kurdish sentiment.
Imagine an April in Iraq that never ends...