How we cite our quotes: (Chapter.Paragraph)
Quote #4
At Fort Wingate, we ate lunch and were sworn in as United States Marines. (9.15)
Chester and his buddies are officially sworn in as U.S. Marines. This marks their formal commitment to defending their country (and they get a yummy lunch to mark the occasion).
Quote #5
"When the time comes that you go to battle with the enemy, I know that you will fight like true Navajos, Americans and Marines." (9.68)
These are the words of the commanding officer of the base where Chester and his Navajo buddies complete their basic training. The officer's words present the Navajos' three identities—Navajos, Americans, and Marines—as in sync. There's no contradiction between these identities.
Quote #6
We Marines cheered our Naval brothers in arms. On shipboard, Navy men and Marines often harassed each other [...] That day, though, all of the rivalries were forgotten. We thanked God for our sailors. (14.92)
Just because everyone fights on the same side doesn't mean that they all get along. Chester's comments here make it clear that there are conflicts within the U.S. troops, but when push comes to shove, they're rooting for one another.