- "They do not deserve your protection."
"It's not about deserving. It's about what you believe. And I believe in love."
"Then I will destroy you!"
- ―Ares and Wonder Woman[src]
- "It is Ares who has these Germans fighting. And stopping the God of War is our foreordinance."
- ―Diana to Hippolyta[src]
After the German invasion of Themyscira, Steve Trevor informed the Amazons that the war to end all wars was currently raging in the world of man. Convinced that Ares is behind it all, Diana left the island alongside Trevor to go and stop the god of war, which in her mind would end all of the fighting.
After arriving in London, Diana and Steve, together with a small support group, headed to the front to covertly search for some sort of large offensive being planned by General Ludendorff and Doctor Poison. Ultimately, the group discovered a massive factory producing huge amounts of poison gas, which was to be flown to the United Kingdom to decimate London.
- "I used to want to save the world - to end war and bring peace to mankind."
- ―Diana, reflecting on her introduction to humanity[src]
Either because of her defeat of Ares, or because the signing of the armistice, or a combination of the two, World War I ended. Diana returned to London along with Sameer, Charlie, and Chief, where they all reunited with Etta Candy. While celebrating the end of the war in Trafalgar Square, the group all took a moment to remember Steve and his sacrifice.