Logan West is an agent with the FBI.
Or he will be as the series progresses. When we first meet him he is a drunk, plain and simple. In the first pages of the first recorded adventure, he is waking up in his basement with a killer hangover and, worse yet, a real killer standing over him ready to end his misery. This was by no means the first time West had blacked out from too much booze the night before but it was the first time someone was waiting to kill him upon waking. The would-be assassin had made the mistake of underestimating West, considering his drunken condition, so West survived the encounter but it was enough to let West know a change was needed.
The reasons for West's deplorable condition was guilt, not over anything he had done but what he didn't do. Even though the Marine Corps had no problem with one of their best members of Force Recon, even awarding him a Navy Cross for actions in the Middle East, West felt he "didn’t deserve it, that he’d failed to keep his Marines alive, that he’d been deceived into doing something that was a disaster he should’ve seen coming." Many of the men under his command had perished and West suffered for it.
That action had been four years ago and West was drinking even harder and had been kicked out of his house by Sarah, his wife and the woman who stilled loved him but who refused to put up with him.
Things would change soon, though. Having someone once again trying to kill him and, even worse, then sending people to abduct his wife, would energize West and give him a renewed reason to live. And once he had purpose again, Logan West was a formidable opponent.
As the man in that basement, and those who went after his wife, and many more to follow would learn, West was "a man who, once committed to anything—a plan, a promise, an ideal—was relentless in its pursuit. He evaluated a situation so rapidly that his former platoon sergeant had repeatedly accused him of acting recklessly; however, in each of those former situations, Logan’s judgment had always proven correct and above reproach. He just understood and saw things before others did."
This was a good thing because now that he was "back" to being himself, he was impressive.