IMO there should be international condemnation from Muslim states, instead of excuses about historical colonial oppression
I would like to see this kind of public stance against extremism by religious institutions, too. Be they Muslim, Christian, Jewish, Buddhist, Hindu, whatever.
Sadly, it's not something that is popular with the religious hierarchs. Christian nations' governments are not a good example when it comes to condemning violence and murder in the name of Christ. My own country's official military emblem is a modernized version of a Crusader Cross, for goodness' sake! They never learn, it seems.
That being said, I condemn the violence against and murder of Christians and other groups in Nigeria.