Magnes was a Pacifist activist. According to Israeli professor Aryeh Goren, he considered himself a follower of Mahatma Gandhi and the prophet Jeremiah, and opposed all forms of nationalism by military force. He had developed Pacifist views in 1898 as a result of the Spanish–American War. Magnes believed it to be an "unrighteous" war. Following the assassination of President William McKinley, who had led the United States into war with Spain, by an anarchist activist, Magnes wrote to his parents from Europe that he was not "enraged at the anarchists for it at all. In my opinion, dishonest men in public office are greater anarchists than those who kill a president once in twenty years".