Christians fought wars over schisms in the Church, differences in dogma, and because the Pope told them to...centuries ago. Eventually, for the most part, Christians have become less aggrieved by their differences and disrespect shown to them or their religion. The Enlightenment led to the secularization of society and government. The Middle East hasn't had an "enlightenment" with regards to religion as a whole and its place in society/government.
Also, to suggest that Christianity isn't a way of life is a bit silly. Is it a hobby or something? For the devout of any religion it is a way of life, but the New Testament focuses greatly on grace and forgiveness rather than wrath or retribution. That doesn't stop lots of Christians enjoying some Old Testament justice though.
The situation in the Middle East is similar to that in Europe 500 years ago when the church was the most influential political, spiritual, and societal body.