Peggy has always been short for Margaret. I've known that since I was a kid. There are a ton of different diminutives for Margaret, according to Wikipedia, including the clear ones like Maggie, Meg, and Marge, but also things like Maisie, Mamie, Madge, Molly, Midge, Greta, and even Daisy (because
Marguerite is the French name for a type of daisy).
All Star Squadron in the early eighties had a nice re-imagining of this by showing that the nice had a magical barrier around it placed by the Nazis that prevented super-heroes from entering.
"The nice" had a barrier around it? I can't figure out what that's a typo for.
Deleted the wrong words I think. I will fix it, but it was Europe they couldn't reach.