I believe Islam will be used as a tool of judgement just like God used the Babylonians and other pagans in the Old Testament.
What ISIS is doing sounds like the wrath of God if it is allowed to spread worldwide.
The beheadings are also very prophetic.
I studied Revelation in a Sunday school class, but I wish I had taken the Daniel/Revelation class offered at the small Christian college I attended.
There’s an excellent book I am currently reading called a Sword on the land by Pastor Bill Randles it deals with Islam in Bible Prophecy there’s also Islamic Invasion written by Dr. Robert Morey that was written way ahead of it’s time.