Why do you think that the first part of the film takes place in boot camp? What is the director trying to show us about preparing these boys for war?

In my opinion, the movie opens in boot camp, showing the intiation of the boys into soldiers, in order to clearly capture the change in their lives. The soldiers are in the midst of losing their indentities..... they are becoming a whole..... expected to work together, think together, and fight together, in order to accomplish the desired outcome.