Sweet sugar or sweet coffee?

In the vaguely disorganized Counter-Jihad Movement, we see civilians among the Readership occasionally standing up to asseverate that the (unfortunately) common locution "radical Islam" is wildly unhelpful if not actually counter-productive, since it strongly implies that ordinary non-"radical" Islam is hunky dory (if not also peachy keen).

Being a student of the English language, I know that sometimes an adjective distinguishes a noun, and sometimes it just highlights its already essential nature. I don't know the technical grammatical term for these two types of adjectives, but we can illustrate it with the following:

When we say "sweet sugar" we are not distinguishing a sweet sugar from a non-sweet sugar, since we know that all sugar is sweet. We are just embellishing, sort of poetically -- adding a bit of frosting (pun intended) -- when we put it that way.

When, however, we say "sweet coffee" we are indeed distinguishing a particular cup (or pot) of coffee from other coffees that are not sweet(ened).

So "radical Islam" is a redundancy, like saying "sweet sugar". Of course most who employ this term (in both Mainstreams) don't mean it as a redundancy at all, but as a qualifier, distinguishing it from a broader Islam that (it is obviously understood) is not "radical".

Perhaps the more apposite analogy of a redundancy for Islam would be "poisonous arsenic".

Capisce?