Imagine you have a town full of hostage takers. These hostage takers aren't quite normal but they want to take over city hall and impose a totalitatarian government on their citizens, right after purging a great deal of them. Their one demand is that the police leave the town and leave them alone and let them do things their way. Some, possibly even many, of the people in the town like these people despite constantly getting killed by one of them. The hostage takers have even killed a good deal of policemen in their quest to take control of the town.
Due to the fact that they are losing men the police threaten to pull out of town if the hostage takers don't stop their actions. They realize what will happen if they do this. But It doesn't matter that they are doing some good, saving some lives in that town, keeping some symbolance of order. It doesn't matter that many will be killed after they pull out.
This shows the hostage takers that victory is in sight and they increase attacks because of this. They think, "The fools, pulling out if we DON'T stop attacking." Many more are killed and much of the progress is lost. Because of this the police pull out shortly after and leave the citizens to their own devices.
So how did you like my story, anyone get what its a metaphor of?