Jihad has been called the sixth pillar of Islam. Spread your cult-religion by warfare and this is true. Please look up the Muslim conquests of Persia and North East India.
It's not my cult or religion, but I think the record shows that for much of Islam's history most Muslims weren't fighting Holy Wars or trying to spread their religion by force.
Just what "jihad" means or can mean is another problem. Somehow I don't trust Wheeler and his bizarre comparisons of Islam with the Aztecs' religion of human sacrifice on this.