The problem the West have at the moment is propaganda.
IS want the West to come and 'annihilate' them. It plays in to their propaganda and legitimises their way of thinking.
This is why I was happy that Russia was going in to actually do something as I know the UN/Nato and the US are reluctant as they don't want to fuel the IS propaganda machine.
The problem is the longer IS actually have a country to call home the worst these terrorist attacks will be.
However even if they manage to dissolve the Islamic State and it goes back to Iraqi and Syrian government control all those Jihadis will just disperse around the globe and just create underground cells a bit like Al Qaeda did. However this scenario I think is a lesser evil to the Islamic State.
It seems to be just getting worse.
For me we are in this scenario for two reasons:
1. Taking out the Taliban in Afghanistan
2. Taking down Saddam Hussein
Both of these actions caused a vacuum in power and further legitimised the propaganda and ill feeling towards the West.
The only saving grace is that Iran are not on the same side as IS. If they were, IS would have a huge ally and access to nuclear material and weapons.