What are three moral issues throughout the novel?

Three moral issues throughout the novel are as follows:
1) War
Faulks describes war and its consequences in stark terms:

This is not a war, this is a test of how far man can be degraded.
But as the stretcher-bearers lifted him, they turned his body and Stephen saw that his head was cut away in section, so that the smooth skin and the handsome face remained on one side, but on the other were the ragged edges of skull from which the remains of his brain were dropping on to his scorched uniform.
Jack saw part of Turner's face and hair still attached to a piece of skull rolling to a halt where the tunnel narrowed into the section he had been digging. There was an arm with a corporal's stripe on it near his feet, but most of the men's bodies had been blown into the moist earth.

Through these descriptions, Faulks highlights the horrors of war and the tremendous loss of life involved in any conflict. War will always be an unavoidable reality so long as malicious powers exist that seek to subjugate or annihilate innocents. Yet, the costs borne by those who fight are monumental. Apart from the physical loss of lives, Faulks also shines a spotlight on the psychological trauma endured by surviving soldiers.
2) Industrialization
Faulks also addresses the consequences of industrialization on the working class. In a conversation between Stephen and Rene Azaire, Rene relates how the workers are unhappy about losing their jobs to machines. For his part, Rene is matter-of-fact about his position: the practical needs of an entire economy must outweigh the immediate needs of its workers. Since France must be able to compete with England and Spain, the machines must be tolerated as a necessary evil. 
Rene's position becomes clearer during his conversation with Meyraux. He argues that difficult economic conditions call for extreme solutions. The factories must retrench and invest in capital. Workers who cannot operate the new machinery must be reclassified as untrained workers and their pay must be adjusted accordingly. For his part, Meyraux accuses Rene of paying progressively low wages for increasingly complex labor. Faulks seems to be asking an interesting question here: "Can the need for healthy profit margins ever be reconciled with the needs of the working populace?"
3) Adultery
In the novel, the main characters become embroiled in extramarital affairs that lead to tragic outcomes for others. Stephen Wraysford, the protagonist, indulges in a passionate affair with Isabelle Azaire, the beautiful wife of his host, Rene Azaire. 
Isabelle married Rene out of necessity. The marriage, devoid of all pretensions, is an unhappy one. It leaves Isabelle craving sexual satisfaction, for Rene is not an adventurous lover. Isabelle soon plunges into a torrid affair with the young Stephen (nine years her junior). 
When Rene discovers the truth, he kicks Stephen out of the house. Isabelle eventually becomes pregnant with Stephen's child, but the two do not stay together. Later, Isabelle becomes romantically involved with Max, a German officer. Bewildered at the turn of events, Stephen takes up with Jeanne, Isabelle's sister. 
Later, we learn that Stephen's own granddaughter, Elizabeth, has an affair with Robert, a married man. The adulterous relationships in the novel lead to tragic outcomes for some of the characters in the story: Lisette, Gregoire, Isabel's daughter, and Rene Azaire. Here, you might be able to explain why. Like Stephen (who came from a broken home), Lisette, Gregoire, and Stephen's daughter must navigate precarious futures in the aftermath of adulterous liaisons within their families. We are left to speculate, however, about the future of Elizabeth's son (John).