Kaufman wrote extensively in opposition to Germany during the 1930s and '40s, proposing that all Germans, whom he described as "violent criminals incapable of peace", be sterilized on a mass scale to free the world of conflict.

• Previously, Kaufman had proposed a similar concept for Americans as well, as a solution to stop American children from being sent to fight in foreign wars.

• His writings, especially those in his book titled Germany Must Perish!, were circulated by Nazis to justify their anti-semitism.