Jason Ender is a "field reconnaisance" operative for the State Department.
A spy by any other name, he is one of their best. As such, he has acquired the right to pick and chose his assignments. His criteria is known only to himself but usually centers on the interesting or challenging.
Ender is a man at home in Europe and the Middle East. He is an expert in several languages and speaks several more quite well. This includes numerous dialects of Turkic from several years stationed in the 'Stans such as Afghanistan, Turkmenistan, and such.
Jason Ender had been in the Intelligence business from quite a few years, starting with the Defense Intelligence Agency. It was in that capacity that he became in essense a student of another Chacko character, Stephen Warfield, an NSA operative who had taken him under his wing during the First Gulf War.
While working for the DIA, Ender had been sent to Turkey to take down an embellizer who was living there. He fell in love with the country and the people and the language. Returning to America he made it a point to learn to speak it. This in turn made him very popular to several government agencies who needed a presence there. He picked the State Department which combined his various talents to create the position of field reconnaisance, a combination of investigator and covert operative.
The position carried with it some unique benefits, not least of all was a much higher pay grade and the diplomatic power and immunity of being an attache. Additionally, he was given freedom to choose the assignments, answerable only to the Inspector General. His area of operation was Asia Minor and the Middle East.
Note: In addition to the books about Warfield, David Chacko is the author of another series of mysteries about a police inspector in Istanbul named Levent, a character who plays a major role in the first Ender adventure.