What does Hemingway's For Whom the Bell Tolls reflect?

For Whom the Bell Tolls is one of Hemingway's major works. American youth Robert Jordan volunteered to join the Spanish government forces and engaged in blasting activities behind enemy lines. In order to cooperate with the counterattack, he was ordered to contact the local guerrillas and complete the task of bombing the bridge. In the raging war, he fell in love with Maria, a little girl spoiled by the enemy, thus healing Maria's spiritual trauma. In three days, Robert experienced the conflict between love and responsibility and the test of life and death, and human nature was constantly sublimated. On the way back from the bridge bombing, he gave up his hope of life to others, but his thigh was blown off by a shell, leaving him alone to stop the enemy, and finally gave his young life to the Spanish people. For Whom the Bell Tolls has touched generations with its profound humanitarian power.

No one is an island, and everything is in vain; Everyone is a small piece of the European continent and a part of that continent; If a piece of mud is washed away by the waves, Europe will be smaller, if a cape, if your friend or your own manor is washed away, the same is true; Anyone's death makes me defective, because I am inextricably linked with human beings; So don't ask for whom the bell tolls; The death knell tolls for you.