SO, THIS IS PART ONE.  It is a fine intro, and maybe you are setting the stage to answer the important questions I've posed.  You've clearly answered the question: Which single story had the greatest impact on you and caught your attention?  Why?

You have NOT addressed any of the other important questions yet:
More importantly, how reliable, trustworthy, and believable do you believe that speaker to be? After all, unlike you or me, they were there, at that specific moment in time. Does that give them more or less credibility? Are they objective and factual or do they suffer from too much subjectivity, too much time having passed, too much forgotten? (These are not easy questions... please take some time to analyze what I'm asking for here.)

My first worry is if you spent this much time/space/length on 1 question, will you spend the proper amount on the last three tougher credibility questions.

My second worry often involves the emotions students feel when reading the stories, then going with that emotion only, ignoring the analytical part.

Your paragraph follows, with my interjected comments IN ALL CAPS

Overwhelming hope (NOTHING THAT FOLLOWS HERE IS REALLY HOPE… MORE LIKE HOPELESSNESS) that the war would end was the force that pushed Phan Xuan Sinh forward in the ongoing and never-ending heartbreak that was the Vietnam War. In Christian G. Appy’s Patriots, Sinh shared two different examples that pounded him with hopelessness (SEE?  YES) while he served as a platoon leader for the Army of the Republic of Vietnam. After being informed that enemy troops were set to land a boat near a small village, Sinh took his scout company so as to inform his army when the enemy had arrived. Upon seeing multiple boats with what he thought were rifle silhouettes, a commanding officer was notified and fire opened upon the boats. After realizing there was no return fire, Sinh asked for flares to be sent up to light the area. Only after the light from the flares burst through the darkness was their mistake fully illuminated. The boats were not in fact the enemy, but fisherman and their families attempting to get the timing for the best fishing opportunities just right (AWK). The impact of this realization was felt instantaneous(LY); not only by Sinh for having experiencing (EXPERIENCED - past tense) it first hand, but by myself in the power of his words on the page. When I think of war it is hard for me to realize that innocent people get caught in the crossfire. LET ALONE BEING PERSONALLY RESPONSIBLE FOR KILLING NON-COMBATANTS  (OKAY, GOT IT, WHY YOU CHOSE THIS STORY.  I'D MOVE ON TO THE OTHER QUESTIONS AT THIS POINT)  It also had such a big impact on me because for the first time it made me see the troops as innocents caught in the crossfire. UNCLEAR. EXPLAIN HOW THE TROOPS ARE INNOCENTS? He spoke of helping evacuate children onto helicopters and helping those still alive and it made me realize that these men did not choose to be killing machines for their country, but were made to as the result of a draft.  CAREFUL HERE - WHICH DRAFT?  Sinh of course was not a U.S. soldier, but an ARVN one.  NOT SURE IF YOU WANT TO TALK ABOUT THE PROS AN CONS OF THE DRAFT AT THIS POINT.

Do these comments help?  Clarify a few parts, shorten the end, and DEFINITELY get to the credibility questions, which will certainly be challenging for you (and all students).  Does an emotional story make it historically true?