To what extent is The Human Factor a novel about apartheid?

Greene's work is set in the espionage circles of Cold War
Europe.  The primary struggles of Castle and his life are ones in which the Cold War is
always in the background.  One of the major themes in the novel is how "the good guy" is
difficult to identify in the midst of political and economic ideologies.  Such pragmatic
decisions don't involve a "good guy," and rather invoke different shades of "bad."  It
is here where the discussion of apartheid exists.  The fact that the Uncle Remus papers
in the novel is a plan for collusion amongst the American, British, and South African
governments in the event of a race war in which Apartheid is challenged represents
this.  The novel is one where the Western hypocrisy involving Apartheid is present.
While claiming to stand against oppression and suppression of individuals around the
world, Western businesses and government still operated with freedom, and without
relative conscience, with the apartheid government of South Africa.  Greene writes as
much in an introduction to a reprinting of the novel, saying that the West was as much a
complicit partner in Apartheid as the South African
Government:

They [economic and political powers
representing the West] simply could not let South Africa succumb to black power and
Communism.

It is here where Cold War themes and
progressive concerns about Apartheid converge in the work.