Here is another example how lack of value of the lives of other humans directly lowers the value of your own life. The terrorists who committed the siege on Mumbai were lead to believe that they would come back alive. If the people who trained and armed them didn't value the lives of their indescriminently chosen victims, how foolhardy were the terrorists to believe that their own lives held value?
It reminds me of a conversation I had with a student several years ago. Throughout his questions and my responses, I wanted him to see that once you start dividing and classifying humans (in this case, black/ white and christian/ not christian) and then you place different values on humans who can be labeled with different classifications, you've lost. Maybe today you'll be in charge and deciding that your group has value and granting yourselves privileges and prestige- but the system of division, categorization and then judging and valuing humans based on their grouping is a monster. The idea the one human can be of more or less inherent value based on grouping is a mentality that devalues human life in general. As history shows, the people who hold power and make the rules, inevitably change. And those who thought that they were making gains for their own lives, their own people, can just as easily fall victim to their own inhumanity.
My uncle lead me to an interesting article in the Economist that links petty lawlessness with increase in other crimes. It's termed "The broken windows effect" I think we can see the same idea playing out on the world stage in terms of increased terrorism.