Historically, Fascism has been viewed as a radical totalitarian political philosophy that combines elements of corporatism, authoritarianism, extreme nationalism, militarism, anti-anarchism, anti-communism and anti-liberalism and having strong leader and central control (ala , Germany, Italy & Spain in the '30's).
However, it seems that we cannot get our heads around radical Islamism with it's franchised decentralized organizational structure where small groups of Islamists can take independent . Nor do we seem to have figured out how to fight this multi-headed hydra - other than to fight it WW2 style and that's probably why many are more comfortable in using WW2 enemy terms for the current enemy.
If that doesn't work we can call them Japs... ;)
Interesting you should mention the Japanese. Islam seems to strongly resemble shinto of Imperial Japan but less tied to a "homeland". It was an extremely effective vehicle for a uniform indoctrination of extreme nationalism, militarism, and official state propaganda.