There will be peace according to islamists after the entire world submits to their caliphate. When the entire world is Islamic. That’s the only peace they know. Until then, it’s pure war, rape, slavery, pillage.
Its fairly illogical - from its very beginnings, Islam has been based on conquest and stealing the resources of others.
What happens when they have pillaged the entire world? Will they suddenly learn how to create wealth and civilization?