A "ruthless leader" refers to someone in a position of authority who is unkind, cruel, and shows no mercy or compassion towards others in their pursuit of power or goals. Full definition
Business Insider put together a list of the most ruthless leaders of all time featuring men and women who employed merciless tactics to achieve their political and military agendas. (businessinsider.com)
«It tends to be forgotten however, that the most ruthless leaders in the Second World War were atheists and secularists who were intensely hostile to both Judaism and Christianity» and «Later massive atrocities were committed in the East by those ardent atheists, Pol Pot and Mao Zedong. (religion.blogs.cnn.com)
@geoffrey blainey - «It tends to be forgotten however, that the most ruthless leaders in the Second World War were atheists and secularists WRONG - hitler was a catholic not atheist. (religion.blogs.cnn.com)