By taking the fight to them. I have seen some of their castles in Jordan a days drive from where I work in Saudi. It make me sad to see them in ruins...they were magnificent far greater than the Moslem imitations.
Of course the Crusaders were also liberators. All of the Middle East beyond Iraq and Saudi and the entire coast of North Africa had been Christian for nearly 400 years before it was conquered by the Arab Moslems and there were large Christian minorities there who welcomed them ass what they were - liberators from Moslem oppression. This was not an "invasion" but re-conquest and unfortunately it was not permanent.
I look forward to the day when Istanbul regains its former name of Constantinople.
One of the greatest, Kerak castle, which held out for a year against the Moslem hordes and who the ancestors of one of my colleagues helped build when they were Christians.
