Commander Craig is an agent with Alert Command.
That, in turn , is part of the Investigation Corps, an elite outfit inside the military organization, United Worlds Space Fleets. Alert Command is the agency that sends in people to learn what the problem is and who is causing it. Then, if the situation is big enough or dire enough, units from the Fleet can come in to blow up the bad guys. If that is not feasible or prudent, it would fall on the agent on the ground to take care of matters him/herself.
Craig is a bruiser of a guy who enjoys a good drink in a bar with a lovely lady, a good fight in a bar over the lovely lady, and then time alone with that lovely lady to make it all worthwhile. He gets his share of drinks, fights, and ladies in his missions.
More when I have finished the books.