nice story so far read it month ago just never review but anyway not bad for a first story.

Good introduction there! Looking foward for the next chapter!

nice start :) looking forward to reading more

Well, looks like you've finally decided to join the trend and write your own story LOL. Welcome to the dark side, I mean, welcome to fanfiction writing :)

This was a nice introduction. It's always nice to know the background of a new character. I'd like to see how he will develop later. This is pretty solid writing, as far as I'm concerned. Not really any typos that I could point out. However, maybe you should space out the dialogue from the descriptions.

For Example: When Justin arrived at the barracks, he knocked on the door. "come in" A deep, muffled voice said through the door.

Instead, you should write it like: When Justin arrived at the barracks, he knocked on the door.
"Come in," a deep, muffled voice said through the door.

This way, the format is more formal, but it's not a major issue. Also, I don't think it's necessary to write 'flashback' and 'end of flashback'; instead, just insert a horizontal line to separate the flashbacks and paragraphs. But again, not a major issue; I'm just pointing this out so that your story will look a little more formal.

Overall, you did a good job so far. Keep it up!

Wow, this is some really great work Silly Goose! I have been looking forward to reading some of your writing that isn't just in an Rp. I was looking forward to good stuff too, and this didn't dissapoint.
The method of the flashback worked really well, I liked how it gave you a backround while also explaining what kind of a person he was before he got into the REAL action of the storyline, or you're suddenly discovering the kind of character Justin is in the middle of a firefight. So that was nice.
The first paragraph of the flash back is really cool, I haven't heard an 'argument' placed so tastefully in a story before. It was really well orchestrated, and despite the fact you didn't kill it with the adjectives describing how they spoke, the dialogue was very well written. I liked the overall course of events, how it was paced. I can imagine Justin very clearly in my mind, nice job.
And in addition, I enjoyed how the Commander was all like "well, yeah, you're second best" and Justin just kind of takes it in. I would have thrown a fit if someone told me that to my face... Just shows how cool Justin is!
Okay, I promised myself that i wouldn't be too critical, but before i wrap up this review, a few reminders to you, just on some improvements you could try.
A new line of dialogue starts a new paragraph. So instead of- "The Commander would like to see you." the 22 year old Staff Sergeant said to Justin. "ok" Justin said." You would have-
"The Commander would like to see you." The 22 year old Staff Sergeant said to Justin.
"Ok." Justin said.
And additionally, each line of dialogue (in the quotes) starts with a capitalized letter. Like you have 'ok,' it would be "Ok."
As for my favorite part of all of this, I would have to say the title. I always find i have the hardest time coming up with a title for a piece of work, this one is just plain and flat out great. I love it, look forward to the next chapter :)