John Allison is an arms dealer.
While he does experience occasional setbacks in business, for the most part he has proven quite successful and makes a very good living selling armaments to different countries. Not only does he usually have the agreement of the American government for his trades, many of them are at their request. When the CIA in particular wants to ensure that a banana republic or rebel force has enough firepower to promote their agenda, it is often to Allison they go to broker the deal and handle the footwork. For that reason, he has small but profitable offices in several big cities around the U.S. and Europe.
But sometimes there are factors that don't like his business. Between peaceniks and those on the other side of his clients, Allison has to know how to use his merchandise even better than the purchasers. And he does, again thanks to the CIA, though not for that reason.
At the end of WWII, Allison, serving in the Army in region of Hungary, fell in love with the area and kept in touch with those he fought with there. When the CIA, under orders from the government, looked for volunteers to go help rouse the Hungarians against the Iron Curtain control, he stepped forward. Two years of intense training in languages as well as covert operations followed before he was sent into Hungary to help them win their independence. When the Russians moved in and the promised American aid never came, he watched the slaughter of hundreds before barely getting out.
Now with that experience, he often works with and sometimes on behalf of the CIA but his distrust is never far away.