True, we do not. However, divisions between Christians in this day and age are not such deep or, let's say, unreasonable like between Muslims, obviously. All recent conflicts that may actually have religious elements (like the old SFRY) are much deeper than plain religion. Same goes for the constant tensions between Russia and western countries, not really much religion there.
sure - and the same would be said by a Protestant or pretty much any other denomination of Christianity. my point is - while the Pope can speak for Catholics (and apologize), there is no Muslim equivalent to 'apologize' for terrorist activity.
of course, the point is moot, because these terrorist attacks were not taken out by mainstream Muslims. the Crusades were officially backed by the Church and its leaders.
That is, currently - historically, Caliphs have been religious and political leaders. ISIS claims to take up that throne now, but...