War.

SO, I have been doing a lot of thinking lately on war because of all these discussions we've been having, and the book. But Im still left with feeling unsatisfied. I feel like I cannot grasp a real solution to this problem we have on our hands. On one side, I can see the brutality of war, and how it hurts the individual, and how horrible it can be. But on the other hand, I can see how it could be viewed as necessary and defense. For instance, lets say, we all rally together and decide not to fight. What happens when the one group of people in a far out country decide they are going to kill everyone just for fun? Demanding not to have war, is like asking for world peace. Although it would be ideal, is it truly attainable?