Soldier, Ask Not is a science fiction novel written by Gordon R. Dickson and published in 1967, based on a Hugo Award-winning short story of the same name, first published in 1964 in the magazine Galaxy Science Fiction. It is part of Dickson's Childe Cycle series, in which mankind has reached the stars and divided into specialized splinter groups. It takes place at roughly the same time as Dorsai! and a few characters appear in both books.
Themes from the rest of the cycle are echoed here, particularly the actions of a key person, like Paul Formain, Cletus Grahame and Donal Graeme in the other novels, who can drastically affect history due to his ability to analyze and influence the behavior of others. Unlike the other protagonists, however, Tam Olyn is no hero.
The primary medium of interplanetary trade is in personal service contracts. The worlds are divided into the "loose" worlds, where individuals maintain some control over their contracts, and the "tight" worlds, where personal contracts may be bought and sold regardless of the wishes of the individual worker.
Tam Olyn is an ambitious, vain, angry young man. Orphaned at a young age, and raised by a nihilist uncle, he cares little for others, with the possible exception of his younger sister, Eileen. Following his graduation from school, he is ready to launch his career as a journalist among the stars.
In a prelude to the main events of the book, he and Eileen visit the Final Encyclopedia, a centuries-long project to try and collect and catalog all knowledge. While standing at the center of the index room, Tam is identified as a one-in-a-billion person who can actually hear the voices of humanity while there. The dying director of the Encyclopedia wants him to stay on and succeed him, but an Exotic, Padma from the planet Mara, reads him as having no identity with others, no empathy, no soul. He cannot help the Encyclopedia.
His sister has become engaged to Jamethon Black, a young mercenary from the Friendly world of Harmony. Despite the fact that Black seems a very decent young man, Tam callously manipulates his sister into breaking the engagement.
Shortly, he leaves Earth, beginning his profession as a newsman. In the following five years, he advances in his profession, while his sister emigrates to Cassida, and marries a young engineer there.
While covering a war on New Earth, he finds his sister's husband, who has been drafted, and attempts to keep him out of harm's way by using him as an assistant. The plan backfires. His brother-in-law, along with several other prisoners, is slaughtered by a fanatic Friendly soldier, in violation of the laws of war. Despite the fanatic's execution for his war crime, Tam chooses to blame the entire Friendly culture, and sets out to destroy them.
Unfortunately, Tam has the ability to analyze people and situations, and manipulate them expertly. Padma observes his actions, and tries to put a brake on his behavior, but he will not be stopped. By manipulating events, he creates a situation for the Friendlies that may result in their destruction as a viable culture.
In the culmination of events, he arrives to cover a war on the planet of St. Marie, a small agrarian world. On one side are the Dorsai mercenary forces hired by the government, led by the identical twin brothers, Ian and Kensie Graeme. The twins, who appear in a number of other stories, are opposites in every way. Kensie is warm, friendly, loved by all, and a great leader of men. Ian is cold as ice, analytical, and a great tactician. He is respected and feared.
On the other side are a group of Friendlies who had been misled into supporting an abortive local revolution. The Friendlies are led by Jamethon Black, whose engagement Tam had broken years earlier. The Friendlies are hopelessly outgunned and outnumbered. Tam has manipulated the situation so that not only will the Friendlies lose, but their ability to hire out their soldiers will be crippled, possibly leading to the end of their viability as a culture.
In the end, he is thwarted only by the faith of Black, and the honor and courage of the Graeme brothers, despite the incredible cost to them. The best qualities of the splinter cultures defeat the worst qualities of Tam Olyn.
As Padma explains to him, had he succeeded, not only would a necessary component of the human spirit have been lost, but the entire balance of power among the worlds would have been horribly upset. Eventually, Padma manages to break through his shell, allowing Tam to grow into more of a human being, and take his place at the Final Encyclopedia.
A key event in the war, barely mentioned in this book, is the death of Kensie Graeme, and the manner in which his brother's honor prevents the bloodbath which could have resulted at the hands of Kensie's angry troops. These events occur after Tam has left the planet. The story is told in great detail in the short story, Brothers.