Jean Echenoz, extract from Envoyée spéciale, suggested translation
It was General Bourgeaud; he was a 68 year old veteran of the Action service, (which dealt with planning and executing covert operations) and he specialized in smuggling in or out sensitive individuals for intelligence purposes.
Due to the length of time he had been in the service, his superiors had little by little cut down his responsibilities, though, as gratitude for services rendered, they had left him the use of his office, an orderly and his full salary. He no longer had, though, an army vehicle. He had no intention of being pushed out completely, however, and so Bourgeaud kept his hand in and set up a few operations on the sly. This was to keep himself busy. And for the good of France.
Opposite him, also dressed in civilian clothing, was Paul Objat. He was half the general’s age, quite a good-looking, soft-spoken fellow with a calm expression, showing the trace of a permanent smile which was as reassuring as it was disconcerting, reminiscent at times of the expression of the actor, Billy Bob Thornton.
“I might have an idea,” said Objat. “Well, think it through, then”, the general said, encouragingly before explaining more about what he had in mind.
“What you must do above all, you see, is put her through a kind of purge, once we’ve found her. We need to take her out of circulation completely for a while before her mission begins. Give her a sort of isolation treatment if you wish. That kind of thing changes someone’s personality. I’m not saying it destroys someone’s character, but it produces more appropriate reactions, it makes the subject more ductile.”
“What do you mean by ‘ductile” asked Objat. “I’m not familiar with the word.”
“Well, let’s say easy to manipulate, obedient, flexible, malleable, do you understand?”
“Alright” said Objat, “I think I do. I’m thinking I might even have several ideas”…
“Let’s not get carried away here,” said the General, trying to calm the other man down as he himself had refined his own resolution.
“When I speak of this purging treatment, which I feel is needed, I feel it wouldn’t be a bad thing to begin by provoking a state of shock, not worrying about making the person a little scared if we have to .”
 To begin with, you should read the passage at least twice. Coming across such expressions as « faisant fi de » and « au vu de », and given that we speak here of « l’intégralité de sont traitement » and not « tout le fric qu’l recevait avant », we see that we are in the presence of a fairly formal style, which will become less so as the words are quoting in direct dialogue later in the passage.
 Better not to begin the sentence with an ING form.
 The expression « duty of confidentiality » exists and is fine here, if a little legalistic in tone.
 Once learners have realize dthat the English verb « to precise » does not exist, they are faced with the problem of how to translate « préciser ». Sometimes it can be translated by « clarify » (Vous voulez bien préciser les raisons de votre plainte). But here it is not about making clearer but about informing for the first time.
 This adjectival structure is preferable, and, of course, you must not be tempted to add an « s » to the word « year ». Remember expressions such as « a ten man team » or « a two hour exam ».
 Far better, as often, to add a verb and use verbal forms in the English translation.
 Not personalities.
 Do not forget to add a verb.
 I liked « an angular face ».
 No contractions for this register. I mentioned last week when we translated an extremely informal passage from Anna Gavalda that contractions might be used becausee the passage was extremely informal. This one is not, as is almost always the case.
 « Shall » gives a more solemn tone here than « will ».
 “Later on” is a little too informal.
 The main timeline reference in French is expressed by the present; in English the main timeline is expressed by the preterite. See here https://www.lawlessfrench.com/grammar/historical-tenses/
 Always good to use a phrasal verb rather than a Latinate one.
 A structure with « no longer » is better here than a structure with « anymore » which is more informal.
 In French this is in the historic present, but in English in the preterite.
 The expression « to be put out to grass » is good, too. « Refusing to be sidelined completely » is very good.
 Whether you begin a new sentence here or not, the « and » is very highly recommended.
 The expression “in plain clothes” is reserved for the police, not the army.
 Someone tried something like « his expression remindee one of Billy Bob Thorton’s, the actor ». But you cannot do this : once a noun is a possessive (Thornton’s) it can no longer have anothe rnoun in apposition. So you have to write « his expression reminded one of that of B B Thornton, the actor. »
 You may well need to revise the punctuation of dialogue in English : see here : https://en.oxforddictionaries.com/punctuation/punctuation-in-direct-speech I do not recommend following the example of the author and omitting all the punctuation.
 « Adapted » is completely impossible (it is almost always a dangerous gallicism, indeed).