Alas the author was quite accurate concerning effective methods of actually defeating an insurgency. The last time the United States had a successfull venture of this type was the pacification of the Phillipines... brutal methods were used and the resulting backlash from the public once they became aware of the tactics ended careers of both politicians and senior officers... it also pushed us into isolation mode for almost two decades.
The time to stop a guerilla conflict is in it's infancy... we unfortunately had a useless monkey in charge named Bremmer when Al Sadr first gained noteriety. Had we simply arrested him after he had that other cleric assassinated, it would of been cake to deal with the few followers he had. Rather we sat on our hands and tried diplomacy... which increased his viability and made us look weak in the eyes of the locals.
Add to the mix is the fact that all the surrounding states are engaging in a proxy religious war makes the situation far less tenable.