IS as a "State" is coming towards the end of its days. The area it controls is shrinking rapidly and its leadership has been decimated. Abroad it has been restricted to a few "kill a handful of people with a vehicle" attacks (though the effect can still be many deaths). The Belgian and French component has been degraded massively according to European police sources (source: Economist).
I suspect it'll fade down to the kind of obscurity currently enjoyed by Al-Quaeda. There'll be other groups but their abilities will decline over time. One of the sources of this decline is the willingness of the USA to kill terrorists and suspected terrorists using drone strikes across the world (aka extra-judicial execution). They are slowly decapitating these organisations. Whether you agree with the method or not, it's certainly having an effect.
What matters for the future is whether the rump of the organisations can still motivate people unconnected with them to carry out attacks. Another relevant point is whether people will carry on without the motivation from abroad. Who knows? I predict a decline but then I'm an optimist.
Vin
If you are correct in your assessment, that is good. However, the chilling comment about all this comes from DT when he stated that when he was young, the US always won the war, and that he was keen to see the US winning wars again. So if Iran or North Korea is obdurate in ignoring DT's bullyboy demands, would he be prepared to use the might of the US arsenal to subjugate their Governments to the will of the US President. at the risk of a horrendous fallout? What if a rogue organisation bombed a US embassy somewhere in the world, and there were alleged links to Iran? What would his reaction be? It might make the Israeli over-reaction in Gaza look timid by comparison.
Just about sums up that rag. 
