Born in London in 1909, Ambler had by the age of thirty produced a group of novels that would forever change the fundamental nature of the suspense thriller.

In such works as Dark Frontier (1936), Background to Danger (1937), Epitaph for a Spy (1938), and A Coffin for Dimitrios (1939), Ambler eschewed the cloak-and-dagger formula of what he called "the old secret service thrillers" for a new kind of spy story that concerned itself with the psychological, social, philosophical, and political issues of the modern age. He sought to "intellectualize' the older, anemic spy story," Ambrosetti writes, and drew from his intensive reading of Friedrich Nietzsche, C. G. Jung.

Oswald Spengler, and other modernist thinkers and writers to do so.

Current criticism generally takes the view that Ambler's best work is in these early, path-breaking novels. Ambrosetti contests this position, finding evidence of Ambler's maturation as a writer in terms of character development, social and political verisimilitude, and cognizance of moral subtlety. Gone from the novels of the 1950s onward are the one-dimensional ideologues of the collectivist 1930s; in their place are ambivalent, alienated characters, morally confused and psychologically homeless.

In such novels as State of Siege (1956), Passage of Arms (1959), and The Light of Day (1962), Ambler considered the West's post-World War II view of the East - politically and psychologically - as the mysterious, untrustworthy "other." In the five books he devoted to this topic, Ambler took up the theme of the Western traveler on a journey of self-discovery and exploration; as one book followed the next into publication, Ambler's protagonists evolved from a stance of fearful and condescending fascination to one of at least partial understanding and involvement.