Craig Archer is an agent with the Division.
The fuller though unofficial title of this organization is the Special Operations Division. Officially it "carried the fairly non-descript title of Division 5" operating out of the eighth floor of the headquarters for the New Zealand government agency it was a part of - The Security Intelligence Service. We are told in our introduction to the group that for many years the SIS "had never been a major player in the intelligence scene, but with the opening of borders had come more pressure from international partners to get involved". Now when it had to take an action but needed it to remain hush-hush, the SIS would pass the assignment to Division 5, aka the Division.
The collection of recorded adventures are labeled by the chronicler as 'The Division Series' and there are definitely other operatives in the Division which play major roles in those missions. Archer was chosen here to be the focal point because he is the lead agent in three of the five assignments and has a major role in a fourth and a smaller one in a fifth. Other agents who see action are Jack Travis, his son Brad Travis, and Rob Moore.
Archer comes to the Division by way of a lengthy time in New Zealand's SAS with tours in Afghanistan and Iraq as well as other countries in Asia, such as Indonesia, where matters of importance to New Zealand required violent resolution. Archer was especially good at such matters. After leaving the SAS as the most experienced and most decorated soldier in his Unit, Archer spent a period of time in the private sector where men of his talents made a lot more money. But when an offer from a former member of the SAS to join the Division, Archer was more than ready.
In addition to Archer's impressive skills as a soldier and then with the Division as a black-ops agent, Archer has considerable language skills and is able to speak more than passable "Arabic, Bosnian, and Tetum [spoken on the island of Timor], along with a bit of French and Russian".