You are pasting your Judeo-Christian ethics onto an Islamowacko. It doesn't stick.
I understand them reasonably well, but understanding does not imply agreement. If you can't (or won't) see them for what they really are, you have no hope to stop them.
Here's the current US Army Counterinsurgency Manual.
http://www.globalsecurity.org/military/library/policy/army/fm/3-07-22/index.html
It's a pragmatic and realistic document on these matters.