(Check it out - Diana's mission of teaching and peace was actually given to her by Ares. This is something no subsequent author will remember, but that doesn't make it any less cool.)
Btw, that's not true. I was just reading "Gods of Gotham" a few days ago (you actually got me to start buying Wonder Woman... I never, ever thought I'd become a WW fan XD), and Diana reminds Ares that he himself gave her his mission.
Since Diana in GoG references something that happened in this story you posted, I'm assuming they are the same version of the character. I wonder, are these stories still canon, or have they been retconned away from the current version of the character?
And speaking of Areas, what's the deal with he and Cassie? I know little to nothing about Cassie, but apparently he corrupted her with an evil lasso? I thought he said he wouldn't oppose Diana anymore, even gave Diana her mission, so why the heck did he mess with and harm her sister?