being Ex military I believe that there are some up sides to this.... there will of course need to be a serious hard look at those returning but most career military love their country... not those in power. Its called patriotism.
There is an massive amount of upside to this. These guys are far better fighters and better military men then the Shia and getting a mixed Sunni, Shia, and Kurdish Army is the fastest way to end the insurgency. The vast majority of Sunnis just want jobs and money.