Not his best for me.
The plot is a bit thin with a feeling of things only being half explained and no real tension.
The relationship between Prue and Nat didn’t ring true. Presumably, she must have known of Nat’s affair, she being such an intelligent woman, yet she is never suspicious of Nat when he is at all night meetings and disappearing on badminton jaunts. She makes a point not to ask too many questions but with her first hand insights into the service she seems surprisingly to have switched her brain off ... but yet we are also asked to believe that she had in the past partaken in dubious spying deceptions.
As for Stephanie, she remained peripheral the whole way through. Was she tense with daddy because she thought that he had had an affair, even though I think her mother told her otherwise (maybe to protect her?) Also, with her being such a potential high flying academic, it was scarcely credible that she flew the coup to Panama with her Indian boyfriend, contemplating a conversion to Islam and her parents having no reservations and being seemingly left leaning liberal types, like herself, Prue especially so.
With regard to the Anglo American plot, it gave only the scantest of unconvincing details about it, and in conclusion none of the supporting cast of spies came across as convincing.
I love John Lecarre but for me this book was a miss, not a hit.