"We come in peace."
Translation:Wir kommen in Frieden.
By the way, I bought long ago this book in Cologne:
no article here either before "Frieden".
Interesting that on https://www.zvab.com/Hermann-Claasen-Nichts-erinnert-mehr-Frieden/18924857286/buch the description calls the title "Nichts erinnert mehr an den Frieden" with the article... perhaps the person who wrote the description found the language of the title odd or poetic and subconsciously added the article when copying the title.