The key issue with Islamic terrorists, or at least the current crop of salafist inspired fanatics, is their beleif that martyrdom sends them to heaven. They welcome violent death and have no reason whatsoever to consider negotiation, moderation, or any level of compassion towards their victims. ( I don't think we would ever hear of ISIS phoning in a coded bomb warning ). Terrorists from other persuasions have demonstrable, if sometimes deluded, aims and objectives, and generally expect to live to see their ideals materialise.