Beheading is a very old tradition and deterent for anyone that oppose a totalitarian force. Has very little to do with religion.
The use of beheading by muslim terrorists are of course to intimidate and scare the watcher. Look what happens to you if you don't obey...
For me the beheading as such is not more cruel than blow up people at a market or shoot somebody. Even though it has a value of humiliation of the victim, which is not something we accept in a modern society. It's just barbaric.......
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