Charles Jenkins is an agent with the CIA.
Quite a few years ago he left the Agency which is why he is not a little surprised when Carl Emerson, his old boss from the old days would come to his door. That many years separation would seem to make him completely out of the loop. Jenkins would be the first to point out that he was so old school that they don't teach those kind of lessons any more. Furthermore any contacts he might have had would have likely moved on as he did or died off, considering that Jenkins when we first meet him is 64 years old. Interestingly the reasons for his being such a bad candidate for re-contact is what makes him so valuable to Emerson.
Jenkins is an African-American though with green eyes, "likely from a recessive gene passed down from Jenkin's distant Louisiana ancestors". He is married to Alex, fifteen years his junior although at their age that hardly makes him a cradle-robber. They have been married for some time, long enough to have their only child, CJ, nearing the tween years. Happily but surprisingly, the Jenkins found they had another one on the way.
Despite being near retirement age, Jenkins remains in quite good shape especially after a year of "intensive and consistent exercise" to get back to near what he once was. Jenkins stands an impressive 6'5" and his weight is once again 235 pounds, just ten pounds heavier than his peak weight when he'd worked as a CIA case officer.
Jenkins makes his living running a security company called CJ Security after their son. His firm "provided services for the Seattle-based investment company LSR&C. The company's CFO, Randy Traeger, was a fellow soccer parent who had approached Jenkins after learning that Jenkins had security experience working for [a prominent] Seattle attorney and his clients. Traeger explained that LSR&C was expanding quickly, with satellite offices in San Francisco, Los Angeles, and New York, and that it intended to expand overseas. Jenkins could coordinate much of the security work - protecting employees as well as wealthy clients who visited the office - by phone, thereby avoiding commuting an hour and a half in ever-worsening Seattle traffic." All of that is extremely important to remember as the activities of Jenkins unfold.
Back to the question of why the CIA would come knocking on his door so many years after they had amiably parted ways. Emerson explains to Jenkins that the Millennials had by now taken over operations at the Agency and that meant that the reliance on electronic means to gather intelligence and to effect desired changes was not only common, it seemed to be the only way they knew to operate. The assignment that brought Emerson to Jenkins' door needed old-school, "boots on the ground", methods and when Emerson thought back to agents he knew who could operate like that, he thought of Jenkins. Add to that the fact that the mission in question was in Russia and Jenkins had been trained in Russian back then, and it looked like he was the best choice available.
As to why someone so far removed from the old days with a family to take care of and a business to run would consider even a temporary change like being asked, money was tight and his main client was behind on its payments and the things were getting iffy. The job offer with the ready cash was too tempting.