It is well known that World War I happened completely unexpected. Everyone thought only in terms of short victorious military operations. And then suddenly they were in a swamp.
This is no coincidence. When people know here is a danger for large war they tend to take precautions not to let minor conflicts get out of hand. But when they feel safe to prevail arrogance often gets the upperhand.
We see this arrogance in Syria too. We keep hearing that just a little bit more support for the FSA will help the rebels win. In fact the only thing that changes with more support for the FSA is that the daily death toll rises. As I have written before a Libya-style victory in the Syrian context could easily cost the lives of 200,000 people. (In Libya 30,000 people were killed. Syria has a population that is three times as large, better defendable terrain and sharper ethnic divisions.) If our leaders would be open about this risk they would feel pressured to seek some compromise. But as long as everyone keeps hiding behind the idea of a speedy victory the conflict is doomed to go on.