In Northern Ireland we refer to these blame games as the "politics of competing grievances".  i.e you guys have killed/tortured/discriminated against our guys more than we have etc.  But at some point someone has to shout stop. Otherwise you become trapped by the logic of your oppressors.  Europe has a big contribution to make - we got to that point 60 years ago.

"It's a mystery to me - the game commences, For the usual fee - plus expenses, Confidential information - it's in my diary..."