One of the attractions of spy novels is that they persuade those of us who lead humdrum lives - that is to say, the great majority of us - that we are surrounded by deep and important intrigues. The man or woman sitting at the next table in a café or restaurant speaking to an interlocutor in a hushed voice may be involved in a game of ­double-­dealing upon which the fate of countries depends. Therefore, the world is not as dull as we suppose.

It sometimes seems as if the need for espionage springs eternal. As soon as one enemy is defeated, another who must be spied upon arises. Therefore, fears that John le Carré, whose most celebrated work was about espionage during the Cold War, would find himself without a subject after the fall of the Berlin Wall were mistaken: Islamic fundamentalism rushed obligingly in to fill the gap for him.

The need for spying in the new situation was obvious; indeed, the situation was particularly suited to le Carré's rather convoluted style of narrative because of the inherent difficulties of distinguishing between terrorists on the one hand and ordinary peaceful citizens on the other, sympathisers being somewhere in between the two.

In A Most Wanted Man a half-­Russian, half-­Chechen illegal immigrant to Germany with a past as a Muslim activist becomes the object of the unfair and unscrupulous attentions of German, British and American spies. As usual in le Carré, the spies are as much concerned with doing each other down as with the ostensible object of their investigation. The illegal immigrant is befriended by a radically, though not implausibly, humourless German female civil rights lawyer and an unlikely and unlikeable British private banker, both of whom are "turned" by the intelligence services of their respective countries.

Although le Carré is clearly sympathetic to the Muslim characters in his story, making them morally superior to the Westerners, they are unrealistic and almost ­zombie-like. They are caricatures, and no doubt Edward Said, if he were still alive, would accuse him of orientalism (in this instance with some justice). The convolutions of the plot are so great that they are difficult to follow, and unfortunately none of the characters is sufficiently sympathetic for us to care in the slightest what happens to him.