I've seen a few comments saying that this is a tribal war or that "we didn't start this". Sorry but not strictly true. If the West hadn't meddled in the Middle East, none of this would be happening. The citizens of Libya and Iraq had better lives under the dictators that we removed than they do now and they blame us for that. Now we are bombing Syria and innocent people's lives wil be destroyed/affected much more than the terrorists' - those innocent people left behind will blame the west for killing their family members, maiming them and livelihoods and so the hatred grows. It could be said that the west is a very efficient terrorist factory.
Now that we have this problem, we need to accept these facts and change our strategy. Everyone knows that bombing doesn't solve any problems and only makes things worse all around. It's all a bit of posturing for the benefit of us here at home so that we feel the government is "doing something". The only way to deal with Isis is to outsmart them instead of playing into their hands by bombing them. But no, that requires intelligent thinking when our governments are only interested in their approval ratings or the next election.