If you go to GPA's wars list you'll find that several people from GPA have been attacking Suicide Squad. I'm lazy so I'm not going to list them all, but you can see for yourself: https://politicsandwar.com/alliance/id=624&display=war
Anyway, I also counted that out of the past 50 wars on GPA's war history, 23 of them have been with Suicide Squad members.
0.o