By Brian's third tour in 2005, he was slamming the "near beers" you could buy on base that smelled like the real thing and had a very low alcohol content. He'd also get real beer in care packages from friends and family that didn't realize he was addicted.
His soldiers would sometimes smell the alcohol on him, but Brian said he'd always have an excuse to brush it off.
When a potential fourth tour raised questions about his physical ability to lead his command -- he'd had multiple shoulder surgeries and had mesh implanted in his abdomen -- Brian was put into the Army's Warrior Transition Unit for injured soldiers. And that's where he realized he had to stop drinking.
He called his wife and told her he was going to get treatment. He later found out she'd already been planning to take the children and leave him.
Tarantino, a retired Army captain, said stories like Brian's drive home the need for more attention to combat-related mental health issues.
"Alcohol abuse is a symptom of the larger problem. It is not the larger problem," he said.
Army brass rhetoric has repeatedly sought to assure the public that treatment for any mental health problems will not negatively affect a soldier's career, but some say they still fear being seen as weak.
"There is a stigma with saying 'I need help,'" Tarantino said. "We're all taught to be strong and macho and we can lift the world on our shoulders."
In Bayas' case, his problems with alcohol went back years, even before he deployed to Iraq.
His attorney, Miguel Villalba, said Bayas, 36, had curbed his drinking after two DUI arrests in the 1990s, while he was in the Army.
But after pulling his best friend's body out of an exploded tank on his first tour in Iraq in 2004 and going through a divorce after he got home, he went back to the bottle. And, his lawyers argued, it was no secret he had a problem. Looking at his 18-year military record, "his alcohol issue was never really addressed."
"That he had a drinking problem was known to the world," Villalba said. "And this was happening at a time when he was being given all kinds of commendations."
The drunk driving accident that killed the 19-year-old college student happened just 10 days after Bayas got back from Iraq. He plowed through her car, which was stopped for a red light, going 60 mph without ever slowing down.
When police on scene asked him where he was headed, Villalba said, Bayas responded, "I was on my way to get my men. I was in Iraq. I was on my way to get my men."
Bayas, his lawyer said, was not diagnosed with post traumatic stress disorder until after his arrest. He pleaded guilty to the manslaughter charge.
"He accepted full responsibility for it," Villalba said. "The effects of what has happened have been ravaging" for Bayas and the victim's family.
The majority of the soldiers seeking counseling for alcohol abuse are young -- 18 to 25 years old.
Army spokesman Hank Minitrez told ABCNews.com that they are trying to do better with reaching the young soldiers earlier.
"For many, shipping out for the Army is the first time away from home for our young soldiers, so they are experimenting with life so to speak," Minitrez wrote in an e-mail. "We are also dealing with younger brains that have not fully developed their executive functions -- that little guy on our shoulder that says, 'Don't do it!'"