What is the main conflict in The Iceman Cometh by Eugene O'Neill?

The world of the play is a cruel place. Despair is a constant presence, love only an illusion, and death something to which one looks forward. Relief comes in alcohol and pipe dreams—groundless hopes for a future that will never arrive. Some critics find hope in the characters' camaraderie and endurance. Others consider such a reading too optimistic, believing O'Neill's vision to be unremittingly dark.