Brutality of war
Remarque writes in the epigraph that his book will describe the men who were "destroyed by the war," and after that All Quiet on the Western Front is a nearly ceaseless exploration of the destructive properties of The Great War. Included are two detailed chapters about fighting at the front and in the trenches (Chapters Four and Six). Remarque smashes whatever romantic preconceptions the reader may have about combat in his descriptions of rat-infestation, starvation, nerve attacks, shell-shock, and inclement weather--to say nothing for actual combat and the deadly zone of no-man's-land between enemy trenches.
The reader is also introduced to all the new forms of assault World War I developed--tanks, airplanes, machine guns, more accurate artillery bombardment, and poisonous gas. The consequences of war are given due consideration--Paul watches friends die, sees dislocated body parts, and tours a hospital of the wounded. Each time Paul counts the thinning ranks of his company, we are reminded that all the fighting is only over a small piece of land--a few hundred yards or less--and that, very soon, the fighting will renew over whatever was gained or lost.
The young soldier's alienation
To add to the discussion of war's destructive properties (see Brutality of war, above), Remarque comments in the epigraph that his novel is primarily for "a generation of men who, even though they may have escaped the shells, were destroyed by the war." This generation is Germany's youth, pushed into the war by their nationalistic elders for a cause they have little stake in, and transformed into desensitized zombies by a war too brutal to endure. Paul's flat tone throughout the novel emphasizes this numbness: he often passes off a friend's death as if it is a common occurrence--which it is. If the soldier allowed himself to feel emotions, he would die far sooner, or go mad. Accordingly, the soldiers either make light of war--they bet over an airplane dogfight, for instance--or become pragmatic rather than sentimental (the fight over Kemmerich's boots, for instance). Paul vows to repress his feelings until after the war, but even he cannot deny the profound pain he endures.
Paul's disconnection emerges again when he visits home. He does not allow himself to bond with his dying mother, and regrets having come home and opened emotional wounds. He has further trouble connecting with the rest of his family and other civilians, none of whom he feels understands his plight, and it is clear his alienation also springs from his disconnection with the past. Like most of the young soldiers who joined the war after they graduated from school, he can barely remember what his life was like before he joined the military, and what he can remember now seems useless to him. Moreover, he cannot imagine any future after the military; the adjustment to civilian life and an occupation seems impossible. The young soldiers are caught in a nihilistic no-man's-land between the irretrievable past and an unfathomable future.
Paul's generation feels betrayed by its nationalistic elders like Kantorek, and by those who glorify war, such as the French brunette who is interested in Paul only as a romanticized soldier on the brink of death. The only thing reducing the soldiers' alienation is their intimate bond with each other (see Unity among soldiers).
Nationalism
Nationalism is the unswerving dedication to one's homeland, and it swept Europe in the years leading up to WWI. Kantorek, the boys' former schoolteacher, epitomizes nationalism; Paul describes how Kantorek rallied his pupils with patriotic speeches and bullied them into volunteering for the war, ridiculing them for cowardice if they stayed at home. However, Kantorek and his generation are not the ones dying in the war. It is the "'Iron Youth,'" as he calls them, who give up their lives for the political power games of a few global leaders.
Paul is bitter about the nationalism that has forced him and countless others to enter the war, but he manages to use it for humane purposes. He unites with the Russian prisoners through a universal language, music, knowing that arbitrary political powers have made them enemies. He also empathizes deeply with the Frenchman he kills, seeing past the man's nationality and into his life (he discovers his name, occupation, and family situation). In fact, Paul kills the Frenchman in the no-man's-land between enemy trenches, the only remaining place in Europe not owned by a particular country (although, of course, bitter fights take place over its ownership).
Unity among soldiers
The first word of the novel is "We," and Paul's typically first-person singular narration ("I") frequently slips into the first-person plural voice. The one good thing that has emerged from the war, he often contends, is the comradeship between the soldiers. Disciplinarian training intent on breaking down the soldiers' individuality, and the horrors of war, bond the men in ways civilians cannot comprehend. They do everything together, from eating to using the latrines; even dead bodies in battle are used as cover for the living. Sexuality plays an important role in their all-male camaraderie; they go on amorous adventures for women (the Frenchwomen episode) or help others have sex (as when they arrange the conjugal visit for Lewandowski in the hospital). Their intimacy is also tinged with homoeroticism (Paul's fondness for Kat as they cook a goose together goes beyond mere friendship).
Animalism
The soldiers are frequently compared to animals. They eat mass-prepared food together as if out of troughs and use the outdoor latrines together. Kat theorizes that the battle for power within the military is like that of the animal kingdom, and Himmelstoss's hunger for alpha-male power reinforces this claim (as does the soldiers' vicious ambush of him). The soldiers are also de-individualized during battle, losing their humanity. Almost as a response, animals play a more important role at these times; horses are used and wounded in battle, rats infest the trenches, and geese pop up at several times.
Words, words, words
In Chapter Six, Paul laments that words cannot do the war justice; in Chapter Seven, he believes they may do it too much justice, making it too real and unbearable. He echoes Hamlet's famous line "Words, words, words"; like Hamlet, Paul is absorbed in his own verbal thoughts, unable to escape from them. Remarque possibly wrote his novel to master and define the emotions of war; perhaps he is the third-person narrator at the end who describes Paul's death.
