Just war theory is a philosophical tradition of applied ethics concerned with the morality of war and peace. It gives society a useful moral guide for tempering the human will to war with the better angels of our nature. The premise of just war theory is that immoral acts like killing can be justified under certain conditions. Broad moral principles and ethical rules specify those conditions so that war’s violence might be restrained as much as possible. Just war theory helps connect ideal moral philosophy with the violent tendencies of human behavior and has been used historically to shape Western cultural attitudes toward war.