How would you guarantee safety for the neigboring Russian provinces? How would you provide access to the world for the Chechen state? (Chechnya is in the middle of Russian territory with the exception of mountain passes to Georgia)
How will you prevent a new influx (through those mountain passes) of Islamist militants? How will you prevent the tribal warfare between Chechens, Ingush, Osetians, Dagestanis and other tribes?
Will the NATO troops do better job than in Kosovo? Will the Bondsteel style American base be established in Chechnya? If Russian government collapses how will you stabilize Russia?
It's tough, this has been going on for centuries.
Russians proved monumentally inept at fighting guerrillas in Afghanistan, and now they're faced with basically the same situation in Chechnya...with a weaker Army.
The problem is that left unattended, or if Russia is allowed to handle this in a ham-handed fashion, they will not only NOT win the war, but in fact increase the number and determination of the terrorists, and the savagery of their actions. Eventually. this will spill out onto the rest of the region, and beyond it into Western Europe.
Certainly granting Chechnya independence must be the end result, leading to Chechens self-policing, but this independence can only be achieved AFTER the terrorists are defeated; anything else would be viewed as a victory.
Perhaps, Russia needs to start a slow turn to Republicanism, with countries like Chechnya becoming a willing part of a Republic of Russia.