in his 2009 book, berman writes that "four radical religious organizations, hezbollah, hamas, the taliban, and the mahdi army, continue to surprise established militaries with both their resilience and their lethality." he credits the hezbollah for being those "who invented the modern high-casualty suicide attack in lebanon in 1982". berman's book seeks to address the question: "why are religious radicals, who often start out appearing benign and charitable and generally avoid conflict, so effective at violence when they choose to engage in it?" previously, berman drew other parallels between hamas, hezbollah and the taliban: