Society has turned the expressions radical and fundamental into bad words meaning violence and off message. Truthfully, we can no longer use those words because of what the media turned them into. The difference is like that of orthodox and moderate Jews or Christians. Or the difference between the Amish and society in general. Radical means fundamental which means by the book. The problems most people have is that the Quran has a lot of specifics about wars that have already been fought. Just as many of the stories in the bible are of battles past. If you really read the Quran with an open mind and can differentiate between what is now and what is in the past or only for certain situations ie: wartime, battle and overt oppression.
A moderate Muslim blends into society, just as a moderate Jew blends into society. But an orthodox Jew, you can easily spot, just as a devout Muslim you can easily spot.
When I was in Turkey, I went to a mosque for the first time and wore a head scarf as a sign of respect. Then I ran into a moderate Muslim who explained to me that only the extremists (not in a negative way but more in an orthodox way) wear the head scarf in public. Moderate Muslims are more lax in regard to hadith and many will drink wine even though it is not allowed, but many Catholics eat meat on Friday, and many Jews no longer wear the yamaka in public. It doesn't mean they are less devoted to God, they are just less devoted to the actual customs and rules (though the only rule to being a Muslim is to know that there is one God, submit to his will, and to acknowledge that Muhammad was a prophet, just as Jesus was a prophet, Muslims respect Jesus just as they respect Muhammad, Moses, and all the prophets. They merely follow the ways of prophet Muhammad, where as Christians follow Jesus.
RT is right about Moderates reporting radicals and either trying to steer them right or putting them out. But radical in this instance would be those that are confused about the true meaning of the Quran. The Quran is actually all about peace. Radicals who think it is about waging war are simply misguided and on a wrong path. The Quran speaks about this in the battle of Badr and numerous other instances in the Quran. Fighting is and should be always a last resort and only when you are being oppressed or when war is waged upon them. They are really a people of peace.
With so many from other religions trying to tell Muslims why their beliefs are wrong, goes against the golden rule of most religions: Judge not, lest ye be judged. This simple fact is that each religion has areas of "ambiguity" to an outsider where unless you truly study it's easy to become misguided in any religion.
And now with our words being screwed over by society, it's hard to even speak without that being misconstrued. A great example is the word "gay", gay used to mean happy, now it means homosexual, so you can't say I'm so gay today without being a bigot or offending someone or having someone think you are homosexual just by the word. It is truly a shame what they do to our English language. Just look at when they called Obama articulate which is a compliment and it was taken as an insult. It's as if we are in Babel again but instead of God messing up all the languages, it's the people themselves that are messing up the languages. It will be surprising if we can overcome this huge obstacle of words.
So with the wording of today, a radical Muslim might be like a pedophile priest, way off the correct path... It is up to those in each religion regardless of the name of the religion to be on watch and as soon as you spot someone in your own religion off the true message of the faith, it is up to you and each one of us to help guide them back to the correct path. The path of peace, love and or indifference to anything that is not of peace and love.