My answer to Why don't UN, US and EU just send troops obliterating ISIS right away?
Answer by Desmond Last:
Afghanistan has cost 1.5 million lives. The conflict began in 1979 and continues.
The Russians could not defeat the Taliban.
The U.S et al have not been able to defeat Al Qaeda or the Taliban.
ISIS and Al Qaeda have growing support all over the World.
Killing as many as possible is not a realistic solution as many will hide amongst remote communities.
ISIS and Al Qaeda are spread from Afghanistan to Africa.
Lone Wolf terrorists in the U.S are Americans. The most effective method of combating ISIS and Al Qaeda is to gain the support ISIS have for the West.
Unless this is done ISIS and Al Qaeda will never be defeated.
The only way to defeat ISIS is by a unified legal military response that does not kill more civilians, the majority of who have been Muslims. We must also address the radical use of the World of God by ISIS and Al Qaeda.