On four tours to Iraq, Green has spent more than half his life in the past nine years away from home, missing birthdays, anniversaries and many "firsts" of his children.
"I look at it like a loss," he said. "I look at it as something that I will never have the opportunity to re-live: First steps, first words, first days of school, and there is no type of accomplishment that I will be able to achieve that will meet me with that satisfaction that I wasn't there to take part in."
To this day, the 33-year-old has continuous nightmares about being in Iraq.
One of his most vivid memories, he recalls, is of killing an 8-year-old boy who was throwing grenades over the military's compound wall in Fallujah.
"Once you have taken a life, there is a portion of that person that travels with you forever," Green said. "There is a nightmare that continues and continues and continues, and pretty soon you learn to just accept that it's just a living part of you that you won't get rid of. ... I mean to the point where you can smell the air, and you can feel the heat off of the weapon, you can see that individual's eyes, you can see what happened, frame for frame, over and over."
But like many of his fellow soldiers, Green says without hesitation that if he would have to serve in Iraq, he would do it all over again, "the exact same way." The father of three says he is proud to have played a part in history and moving Iraq into a different direction, one he hopes will be for the better.
Iraq and the United States face a new chapter and a new set of challenges as U.S. troops withdraw. For the United States, the growing influence of Iran on one border and Syria on the other is a continuing cause of concern. Iraq continues to be rocked by Sunni-Shia, Kurdish-Iraqi violence and the absence of a strong, stable regime. The threat of al Qeada also remains, but U.S. generals say it's time for the Iraqi security forces to take over.
"We know that al Qaeda is going to do what they've always done," Gen. Lloyd Austin said. "They are going to continue to try to focus on the government and the Iraqi security forces. And the Iraqi security forces are going to have to deal with that, and I think they can.
"They are going to have to work hard at it. They are going to have to improve their intelligence. They are going to have to continue to work on their logistics as well, that's still a work in progress."
For U.S. soldiers leaving Iraq, this week is momentous.
"I stopped, took a second, looked around, smelled the air as only Iraq can smell, saw the sunset," Courter said, laughing, of what's expected to be his last departure from the country. "It was an indescribable feeling, knowing you had been here so much, all the cost of what we have done here. It's finished."