the second last book I read

The Quiet American by Graham Greene.

It's the early 1950s and Thomas Fowler is a British journalist based in French Indo-China; the bit that later became South Vietnam (and later still just Vietnam). He's occupying himself ticking off all the main characteristics of the typical Greene protagonist - exile in a foreign country, largely abandoned wife back home, desultory affairs with local girls, fondness for drink (and in this particular case the odd opium pipe as well), general air of rumpled disillusionment and moral compromise - when he is befrended by earnest young American Alden Pyle.

Pyle has some firm ideas about what needs to be done to resolve the current conflict and, as Fowler soon discovers, few qualms about the methods he uses to do what he believes to be the right thing. Things are further complicated when Fowler's local mistress, Phuong, deserts him for Pyle. Having come to the conclusion that Something Must Be Done following a series of bombings made possible by Pyle's support of the insurgents, Fowler is presented with his own moral dilemma as he prepares to betray him.

If you're a bit sketchy about the historical details (as I was) then the war being fought here is this one, which concluded in 1954. After 5 years or so of peace another war broke out in 1959; this is the one the Americans ended up getting involved in, which was unfortunate for them, but on the other hand led to some really cool films. (The Quiet American has been filmed twice, in 1958 and 2002.) I think the old Penguin paperback edition of the novel that I've got (which I picked up on one of my regular trips to Hay-on-Wye) dates from the late 1960s, in other words at the height of the USA's involvement in the second war, which may have been an influence on the choice of cover picture.

Pyle's well-intentioned but ill-informed meddling can be seen as a precursor to the USA's eventual involvement in Vietnam, indeed the principal characters can be seen as representing the principal characteristics of their countries of origin: Fowler the shabby, world-weary Englishman, Pyle the clean-cut, earnest but clumsy and naïve American, and the policeman Vigot the philosophical Frenchman, shrugging Gallicly while quoting Pascal. As always the main protagonist is a thinly-disguised version of Greene himself, who spent some years as a journalist in Saigon in the early 1950s.

This isn't Greene's best book, it's a little too bluntly polemical for that, but it's well worth reading all the same. If you want somewhere to start I would direct you towards the earlier novels like The Power And The Glory and The Heart Of The Matter.