The writer seems to exhibit copious amounts of Stockholm syndrome for his captors. From that standpoint it was a successful intelligence operation on their part. Iranian intelligence can likely count on him as an asset to answer questions over the phone for them in the future for some time.
Drawing empathy from the victim is a common technique in interrogations such as this. The victim is wholly unaware it's happening. This is clearly the case here, the author makes no mention of being self-aware of these techniques.
