The attack in Mazar-e-Sharif may or may not be a "gamechanger" but it certainly raises heaps of questions about the present and future of the UN/NATO missions in Afghanistan. One Quran burned in Florida leads to several (seven, eight or more) deaths in one of the supposedly more stable parts of the country. The irony is that the globalization that made this transmission belt possible is exactly what these extremists on both sides are fighting--the 21st century. Anyhow, what will be the impact of this?
First, it undercuts the transition process since this happened exactly where NATO and Karzai agreed to turn over security to the Afghans. Even though formal responsibility may not have been turned over yet, it shows that stability means a great many things to a great many people. But to the families of the UN workers, M-e-S does not appear to be a stable neighborhood.
Second, it weakens even more the support in the West for the NATO/ISAF mission. One can hear people thinking "if these people value a book more than people's lives, then we will never be able to work with them." Of course, public support for the mission is so universally low that this event might not make that much of a difference.
Third, it is not clear what this will do to the rules of engagement for the UN and its protectors. There were folks on the ground with guns, but they chose not to shoot at ordinary citizens engaged in a vehement protest that became a riot. If they had fired their weapons and prevented the base from being overrun, the extremists still would have won because "innocent civilians" would have been killed. So, there may be no way to play this well. The extremists have another card to play--mob manipulation. Instead of having more and more openness, the elements of the international community may revert to diminished access.
Fourth, it just feeds the zealots in the US to burn more Qurans. They got what they wanted--more press. So, these guys are certainly not going to take responsibility. They may not even know what the word responsibility means.
This can only be profoundly frustrating all around. The forces of insanity win in Afghanistan and they win in Florida. There is no bright side to all of this. There are too much sunk costs for the international community to pull out tomorrow. However, I would not be that surprised that in 2015 Afghanistan returns to its pre-Taliban, post-Soviet condition--a multi-sided, vicious civil war. With no one wanting to jump back into the mix.