The post war effect in All My Sons is illustrated in several different ways by Arthur Miller.  First, and foremost, the fact that Larry, the Keller's son, is MIA, missing in action for three years, and that Kate Keller will not acknowledge that her son is probably dead, is the most profound post-war effect in the play. 

She clings to the belief that he will return, because everyday in the newspapers, the play tells us, men who were assumed lost were released or recovered and returned home to their families.  So Kate hopes that Larry will be the next man found alive.

The after effect of the war is also reflected in Joe Keller's business and the fact that he, having had a second trial for the criminal charges brought against him by the military for providing faulty parts which resulted in the deaths of several pilots, appears to have recovered from this scandal.  His factory is humming along making refrigerator parts, a reflection of the boom that occurred economically after the war.

Sue Bayliss does not like Chris Keller because he is good friends with her husband, Dr. Jim Bayliss.  Chris has and continues to encourage Jim to give up his medical practice and go into medical research.  Chris is an idealist, he believes in the world the way it should be, not the way it is, and Sue resents his constant meddling in her life because she doesn't want Jim to give up his income to do research which would provide substantially less money.

Sue contends that Chris does not have to worry about his financial security because he works for his father and will one day own the factory himself.  So she feels that he should keep his opinions to himself.

In fact, Sue tells Ann Deever that if she marries Chris that she should move far away from the neighborhood, it would be better for her.