Were the Crusades a Shame upon the Church?

A friend wrote me the other day about the Crusades: 

The crusades are a shame upon the church, correct?  

I wrote back:

The Crusades were an effort to save Byzantium from destruction at the hands to the Muslims, and are not a shame upon the Church. Islam attacked, conquered, raped and pillaged its way across the central nations of the Christian world for 700 years before we finally “fought back” (if you don’t count Byzantium’s endless wars against Islam and Charles Martel and the Reconquista of Spain!). We are, have been since Islam’s inception, in a life-and-death struggle with Islam. They will never relent till they’ve destroy Christianity (and Judaism too, for that matter). 

An Préachán