How is the title of the play All My Sons justified?
"All" of Joe Keller's (note the similarity to killer) sons include his two biological sons, Larry and Chris, and the 21 young men who died in plane crashes in World War II due to Keller's complicity in selling faulty plane parts—cracked cylinder heads—to the armed services. Joe's friend and business associate goes to jail for the crime, but Joe is cleared, even though he is equally guilty. Meanwhile, his son Larry has been missing in action since his plane crashed (ironic) in World War II, and Chris has come back from the war a more mature person willing to take personal responsibility for his actions. He wants this father to do so as well.
Joe justifies his actions as taking care of his family. He says that as a father he had to provide. Ironically, of course, taking care of his own sons led to the death of other people's sons. The title of the play strongly implies that we carry a responsibility towards others beyond the narrow confines of our immediate biological families. If we are all brothers, especially in times of war, then we are responsible for protecting other people's sons, not just our own, by acting with fairness and integrity.
Joe's role as a father is primary to his identity and implies acceptance of a higher level of responsibility than just any man. This is summed up in Chris's words:
I know you're no worse than other men, but I thought you were better. I never saw you as a man...I saw you as my father.
Joe Keller, the main protagonist in Arthur Miller's All My Sons, was a manufacturer of cylinder heads for the Army air force. Unfortunately, he knowingly shipped cracked cylinder heads to be used in planes causing the death of over 20 service men because of plane crashes. His greed for wealth and to leave the manufacturing business to his son was thwarted by the scandal and his deceit. Joe Keller professed to believe that family was important, especially when he wanted to leave his son, Chris, the legacy of a family business. However, his lack of concern in shipping defective parts killed other sons of families in America. I think "all my sons" refers to the fighting men who risked their lives during WWII. They are America's sons, so to speak. As soldiers, they lived and died for our freedom, and Joe Keller did not respect them. To Keller, it was more important to provide for his family than to protect the lives of others. His selfishness was his downfall in this story, and he lost everything because he failed to protect the sons of all Americans.