The US historian James J. Weingartner attributes the very low number of Japanese in US POW compounds to two key factors: a Japanese reluctance to surrender and a widespread American "conviction that the Japanese were 'animals' or 'subhuman' and unworthy of the normal treatment accorded to POWs." The latter reasoning is supported by Niall Ferguson: "Allied troops often saw the Japanese in the same way that Germans regarded Russians — as Untermenschen." Weingartner believed that to explain why merely 604 Japanese captives were alive in Allied POW camps by October 1944.