Over the years I read suggestions that we should forgive Germany, Poland, Russia, the Catholic Church, the Crusades, Christianity, Islam, Egypt, the Ku Klux Klan, etc.
The only "forgiveness" I ever found in the Sources was forgiveness of an individual, by God or by another individual. I never found any mention of "forgiveness" of a country, an institution, a religion, or any group of people as a whole. Is there such a concept in Judaism?
There are hints of that (such as "Do not despise an Edomite, because he is your brother. Do not despise an Egyptian, because you resided as foreigners in his country." [Deut. 23:7]), but it does not rise to "forgiveness".