Despite helping win the war, defeating Ares and still loving humanity, Diana is still left sobered, emotionally broken, psychologically scarred, and devastated over not having been able to save the Belgian village from Dr. Poison, as well as over her beloved Steve Trevor's self-sacrificing death. Indeed, Diana would later claim that she "would never be the same" ever again after World War I. Moreover, in the years that followed, Diana bore witness to a "century of horrors" (Wars, Fascism, Communism, nuclear weapons' deployment, geopolitical brinkmanship, racism, homophobia, genocides, war crimes, propaganda, and etc.), and due to all of this occurring without Ares being there to spread corruption, Diana almost completely lost faith in humanity, coming to believe that humans "made a world where standing together is impossible". As such, Diana resolved to mostly abandon superheroism for 100 years.
The JLA's first trip to the universe is where Owlman is found hacking computer systems to get the info he needs. There, the JLA fights recruits the Crime Syndicate of America has recruited. Their second trip was when Batman followed Superwoman, and defeats her. After taking out Superwoman, he calls the JLA, and alongside the JLA travels to the moon, to get to the Crime Syndicate's headquarters. From there on, every JLA'er fights against their counterparts, and Wonder Woman manages to even win against her counterpart, Superwoman.
The story behind the writing and editing of Wonder Woman can be pieced together from Bender’s papers, at Brooklyn College; Frank’s papers, at the University of Minnesota; and Marston’s editorial correspondence, along with a set of original scripts, housed at the Dibner Library at the Smithsonian Institution Libraries. In his original scripts, Marston described scenes of bondage in careful, intimate detail with utmost precision. For a story about Mars, the God of War, Marston gave Peter elaborate instructions for the panel in which Wonder Woman is taken prisoner:
Due to the format of most golden age comics, the majority of story arcs at the time for all characters were the same, Wonder Woman included. More accurately that is to say that there were not story arcs at all, as issues contained two to three stories, all of which started and concluded within the issue in question. There was therefore not much continuity in Wonder Woman until she reached the silver age. The few exceptions to this were in issues which contained a common theme, such as Wonder Woman meeting some leprechauns and each of the three stories dealing with that. Alternately there were some common themes for the character at the time, one of which was dealing with enemy saboteurs. These were mostly contemporary, and thus started as either the National Socialists in Germany or the Imperial Japanese. Later these became others.