Someone might write an interesting comparison between three thriller writers who happen to be called John. From Buchan to Le Carre is a change from patriotism to cynicism. Grisham makes two further changes, of nationality and profession: from British spy thrillers to American legal thrillers.
Buchan's plots rely on too many coincidences and implausible events, particularly in The Three Hostages. Buchan's own political career seems to have obsessed him with the idea of someone speaking publicly without preparation but carrying it off. This happens at least three times in the novels. Buchan wrote from a different era when he said of the then King of England not, "He liked my books," but "He did me the honour to be amused by my romances." (An old edition of a HG Wells novel listing other works by the same author included titles under not "Science Fiction" but "Mr Wells has also written the following fantastic and imaginative romances: -")
Grisham's novels are gripping page turners throughout. He skilfully connects books with recurring characters and settings. As in le Carre though not in Buchan, it is taken for granted that an assassination may have been committed by agents not of a foreign government but of ours. A new Grisham novel set in the 2000's and referring to emails, the internet, satellites and space aeroplanes reads like science fiction. These three writers bring their readers a long way from the eve of the Great War in The Thirty Nine Steps through the Cold War to the high tech war on terror.