Death and war go hand in hand, and For Whom the Bell Tolls is about war. So almost every major character in the book is forced to come to terms with their own death, and the deaths of their loved ones. They display a variety of attitudes towards death, from paralyzing fear and despair, to resignation, to relative unconcern. One thing that all experience, however, is the way death forces a re-evaluation of one's priorities. The protagonist's attitude towards death changes as the value he gives to his own life changes, and the book explores the relation between the two.
At the start of the book, not only is Robert Jordan not afraid of death, he actively wants to die.
Pablo's fear of death is actually a symptom of a more general despair caused by his guilt over the people he's killed.
For Whom the Bell Tolls is the novel about the Spanish Civil War, and it describes the uniquely cruel reality of war violence in all its grisly details. In this novel, war seems to escalate beyond human control, thwarting the best-laid plans of any commander. It deprives individuals of their loved ones, forces them to kill their countryman, and spreads barbarism. Perhaps most troubling of all, war releases the darkest side of human beings: the lust for blood, the pleasure in slaughter, and the madness for revenge which make killing possible, even desirable, for many of those who fight.
Pablo initially relishes the war because it gives him free reign to satisfy his bloodlust.
There is no single person or authority with real control over the course of the war on either side. War, as we see it in For Whom the Bell Tolls, is the product of large number of individual actions and accidents, which can only be loosely managed by the people supposedly "in command."
Though it is a story of war, For Whom the Bell Tolls is also the tale of the sudden but passionate love between an American volunteer and a Spanish girl brought together for three (and a half) days by a military operation. Each is unprepared for and overwhelmed by the "earth-shaking" experience of romantic love between two people, which neither has ever felt before. Their experience gives to each a new reason for living – the other person – and suggests that the aloneness of the individual can be lost in total union with another. Yet from the beginning it is clear to each that their love may have no future.
Robert Jordan and Maria's love is in fact nothing more than lust. They have no connection besides their sexual attraction.
Robert Jordan and Maria's relationship is based on the inequality of power between the two of them.
For Whom the Bell Tolls is the story of an American volunteer, Robert Jordan, fighting with Spanish Republicans in the Spanish Civil War, kind of like Hemingway himself did. Robert Jordan is there because of his special love for the Spanish people. But this is a love-hate relationship if ever there was one, since through his observations he offers us almost as many reasons to be revolted by the Spanish as to admire them. His position as a foreign newcomer leading a close-knit group of Spanish guerillas also brings him to reflect explicitly on his role as an outsider, and the larger role of outsiders in the Spanish War itself.
Robert Jordan's knowledge of Spanish and his familiarity with Spanish culture make him able to fit in with the guerilla group as well as any Spaniard would.
Robert Jordan does romanticize the Spanish. Many characters simply do not fit into his "stereotypes."
Fighting in a war, as do the characters in For Whom the Bell Tolls, inevitably means having duties. There are the obvious duties to one's cause, or to one's commander. But there are also duties to one's friends, whose lives are constantly at risk. Characters have different understandings of what their duties are, and what they require. Some, such as the main character (when we first meet him), seem almost entirely motivated by duty to the side they're fighting for, and are tempted to regard themselves and other people as instruments. That's much harder to do if one begins to form friendships with the people one fights with.
Pablo is moved by a sense of duty, but his sense of duty is to his band, rather than to the Republic.
Robert Jordan was extraordinarily concerned that his mission would fail after Pablo had stolen the detonators, but never seriously considered abandoning it.
This is the theme one would expect to find in every Hemingway book, and For Whom the Bell Tolls doesn't disappoint. "Being a man" is an ideal of many of the characters, one men hold up for themselves and one women criticize them for if they fail to meet. The war places particularly high demands on "manliness." Courage, and willingness to risk one's life, is one standard used to separate the men from the boys (or women). But perhaps still more important – and central to the protagonist – is the ability to control one's emotions and urges, and to "take it straight" (just accept reality and deal with it – no whining). The protagonist might be seen as an ideal male by those standards.
Robert Jordan subscribes to a vision of "tough-guy" masculinity to which he himself fails to live up.
For Whom the Bell Tolls is about the Spanish Civil War, and the Spanish Civil War is all about politics: it's a conflict between the leftist "Republic" and the fascist Nationalists. All of the characters the novel focuses on fight for the Republic, some of them with a zeal which borders on the religious. Yet what the Republic stands for is somewhat up for grabs: it's a troubled coalition of Communists, anarchists, and those who simply believe in "freedom" or "the people." The optimism or idealism felt by some characters is sharply contrasted with the reality of Republican politics – constant lying, infighting, control by foreigners. The protagonist's loss of a naive idealism is a major step in his "education."
While Robert Jordan might be classified as an idealist because he believes the Republican cause is straightforwardly the cause of "freedom," his position makes sense when it is considered that the loss of the Republicans would mean the victory of the fascists.
Even if he does not consider himself to be a communist, Robert Jordan is still a communist insofar as he is willing to serve the Communist Party without objection to its more doubtful practices.
For Whom the Bell Tolls revolves around the idea of communion between human beings expressed in its epigraph. Connecting to others is the only way to overcome the emptiness and loneliness at the heart of each individual, especially in the hopelessness of war. It's their camaraderie which keeps many of the characters afloat. The most everyday activities and expressions of friendliness – being humorous, telling stories, touching, even swearing together – preserve some sense of normality, of humanity in the midst of "barbarism." The protagonist is transformed by the bonds he forms with the people around him over the course of only a few days.
It is seeing his sacrifice as something he does for his friends that gives Robert Jordan's death a purpose, and that serves as his ultimate consolation.
Many of the characters in For Whom the Bell Tolls find their moral beliefs troubled by the war in which they're fighting. Winning a war requires the use of violence to defeat or eliminate one's enemies; that much everyone agrees. But even if violence is necessary, it's not clear that makes it right. Some characters think it certainly doesn't, and try to find ways of reassuring themselves even as they feel compelled to kill; the protagonist is, with a few complications, one such character. But if killing can't ever be right, how is one to understand what one is doing?
For Robert Jordan, to say that "killing is never right" simply means that one should never feel pleasure in doing it. It does not mean that killing is never justified – it obviously is in the case of war.
There's a thread about the supernatural which runs throughout For Whom the Bell Tolls. Near the book's beginning, another character, Pilar, appears to see the protagonist's "fate" in his palm. The protagonist, Robert Jordan, makes nothing of it, since he believes superstition is so much stuff and nonsense which doesn't "take the world straight." Throughout the rest of the book, there's something of a competition between Jordan and Pilar, who claims to see into parts of reality to which he is simply "deaf." Many of the other characters are inclined to believe in the supernatural, whether filtered through Pilar or through Spanish Catholicism.
Robert Jordan is completely convinced that belief in the supernatural is "superstition," and is only curious about it because it seems so strange to him.