"One morning in 2002, Yadlin recalled, he "woke up horrified" to learn that 15 Palestinian civilians had been killed in an operation. That afternoon, Yadlin called Asa Kasher, a philosophy professor, and began working on ethical guidelines for fighting terrorism. They also asked a mathematician to write a formula to determine acceptable civilian casualties per dead terrorist." (Look at the casual (im)morality of Zionism).