The read for the World Literature group I'm in on Goodreads, this was the first of Hwang's novels to be published in English. The title, The Guest (Sonnim in Korean) is the name that was given to smallpox, a disease which was introduced from the west and reached epidemic proportions after the country was "opened" to western trade and exploitation. Hwang explains in the preface that he chose it to refer to Christianity and Marxism, the foreign ideologies which have divided Koreans from one another. I do have problems with his calling the Stalinist ideology of North Korea Marxist, and even more to his equating it with Christianity -- although I suppose it could be argued that modern Christianity, or at least the Korean version of Christianity, is equally distorted; unlike the situation with Marx, we don't have any idea what Jesus actually stood for. In any case, the forms in which these two western beliefs reached Korea were certainly both disastrous for the people of the penninsula. (I would also note, however, that the religion and culture they displaced were also largely a foreign import, derived from China.) Actually the novel itself does not treat the two sides as completely equal -- while there was overreaction on both sides, the guilt is clearly placed on the Christians, and the way the book is structured, it is largely about the repentance of the Christian characters.
This theme is not what made the novel so controversial; rather, it's that the book offers a revisionist view of the Sinchon massacre. Rather than simply present the novel as a fictional speculation, Hwang made the claim that he was revealing the real truth about the massacre. He apparently based his view on two alleged eye-witnesses, a minister who is the original of Reverend Ryu, the main character of the novel (and who according to some posters on the internet later said he was misinterpreted), and an anonymous person in North Korea. This hardly seems like conclusive evidence, and without questioning Hwang's honesty or sincerity -- it's obvious from his other novels that he is hardly an apologist for the United States or the South Korean government; The Shadow of Arms has a graphic description of My Lai -- I think it is better to treat the book as a fictional possibility rather than as a factual historical novel.
The official North Korean version of what took place at Sinchon is that there was a systematic massacre of almost forty thousand civilians by U.S. troops over a period of forty to fifty days. This certainly seems implausible to me; the two documented massacres by American troops, the 1950 massacre at No gun ri in Korea and the later more famous one at My Lai in Vietnam, were both carried out in a short time by small units and there were in both cases soldiers who refused to join in and eventually broke through the attempted cover-up. That a major operation against civilians was carried out by U.S. combat troops and no one ever spoke out about it, even after they had left the military, doesn't fit in with what I know about the mostly working class American citizen-soldiers -- only a highly professional elite corps like the European colonial armies or a highly fanatical military group like the SS could do something like this. On the other hand, despite U.S. and South Korean claims that it never happened, there seems to be real evidence of some sort of mass killing. That the U.S. military "advisors" may have participated in or even directed a massacre by the South Koreans is far more plausible, and would fit in with the atrocities in Vietnam carried out by Vietnamese troops under the supervision of the CIA in the "strategic hamlet" program. Another possibility of course is a right-wing paramilitary group of some sort, and this is essentially what Hwang is claiming -- an armed Christian youth group animated by religious and political fanaticism.
As presented in the novel, the underlying dynamic was one of class rather than religion, or rather the religious difference was the form taken by the class antagonism. The Christians according to the narrative were the more affluent farmers and petty bourgeois layers (the actual large landlords having already fled to the South), who had become wealthy through collaboration with the Japanese occupation; the Communists and their supporters were mainly among the tenant farmers, and the Christians were opposing the land reform which was giving the former tenants ownership of the land they had been working for the benefit of the landlords and the Japanese corporations. A violent opposition group made up of young Christians had fled to the hills after carrying out acts of terrorism, and armed themselves with the support of various groups such as the Anticommunist Youth Corps in the South; they returned ahead of the American invasion force and decided to exterminate the Communists and their families as agents of Satan. The returning Northern army troops then re-entered the area and suppressed the revolt, of course in turn going too far and killing many uninvolved Christians. The account seems quite familiar to anyone who has read about the alternating massacres of Christians and Moslems from Bosnia through the Middle East and into much of Africa, for example, or much of the violence in the former USSR after the collapse of the Stalinist regime. Some of the Christians at least belonged to a group called the Unification Corps; I couldn't help being reminded of the right-wing Unification Church of Rev. Moon, although I don't know if there is any direct connection between the two.
Leaving the historical controversy aside, the book has an unusual style, being based on the stages of a rite of exorcism; ghosts appear to the main characters throughout the book, and much of what we learn about the massacre is revealed supernaturally. The novel begins with the visit of the protagonist, Reverend Ryu Yosŏp, to North Korea after a lifetime in exile in the United States, and three days after the death of his older brother Yohan, an actor in the massacre. Apart from the ghosts, the narrative is made up of flashbacks and memories as in The Old Garden, but with many more characters' points of view; sometimes it is not immediately apparent whose memories are being given. There is much explicitly described brutality and this is a book that many people would have difficulty getting through. Despite putting the blame for the massacre on the Christians, the book seems very religious, being largely presented through the consciousness of the Reverend and concerned with repentance and forgiveness. There is much praying and many Bible quotations throughout. I have a problem with that whole theme too. It seems that from the original Athenian Amnesty to the recent Commissions on Truth and Reconciliation, the side of the rich and powerful always gets the benefit of any amnesty while the revolutionaries are always persecuted relentlessly. There isn't always forgiveness, of course, and one could point to many "red terrors", but if there is an amnesty it's always one-sided. Compare the treatment of the Shah of Iran or General Pinochet who tortured and murdered tens of thousands of innocent people with the treatment of say Leonard Peltier, convicted after a questionable trial of killing two armed FBI agents coming after him. I'm not for vengeance as such, particularly when the Stalinists punish people for their own and even their parents' and grandparents' class position, but when it comes to atrocities such as Hwang depicts (leaving aside whether events happened the way he depicts, I'm discussing this as a fictional narrative) there comes a point when one must ask, as one recent book on the Holocaust did, whether the living have the right to forgive crimes against the dead.
Although this is probably Hwang's most famous book, at least outside Korea, perhaps due to the controversies, I have to say that I thought the previous novel was better.