In Petals of Blood, Ngugi presents the reader with a complex, multi-faceted portrait of post-colonial Kenya. Although the Kenyan people have managed to throw off the yoke of British colonialism, many of them find that their newly-independent land still has more than its fair share of problems, many of them related to the government's venality and corruption.
Ngugi's critique of post-independence Kenya is articulated in the novel by the character of Karega, who can reasonably be seen as the author's mouthpiece. A radical socialist committed to a complete reconstruction of society, Karega advocates violence among the poor and dispossessed as the only way of bringing down a system based on corruption and exploitation. With their guns and swords, the common people of Kenya will rise up and “seize the wealth which rightly belongs to them”.
Whether Karega's radical socialist vision is the right one, or whether his advocacy of violence is acceptable, there can be no doubt that his ideas provide the basis of a withering critique of an economic and political system that is supposed to serve the interests of the Kenyan people as a whole, but in actual fact places wealth and power in the hands of a corrupt, self-regarding elite.