"radical terrorist" is something interesting. That suggests there could be some "moderate terrorist". Anyone encountered that weird kind of terrorist?
They don't tend to be called 'terrorists'(because, by virtue of being moderate, they use violence to achieve ends that good, upstanding, people agree with); but nothing about being a terrorist actually requires any particular flavor of agenda, just the presence of somebody opposed to whatever your agenda is, and the willingness and capability to employ coercive violence and fear.
Somebody like Sir Arthur Harris would arguably qualify. He was an ideologically unexceptional commander of British air forces during WWII, and implemented the British 'saturation bombing' efforts against civilian targets and infrastructure. As he candidly described it:
"the destruction of houses, public utilities, transport and lives, the creation of a refugee problem on an unprecedented scale, and the breakdown of morale both at home and at the battle fronts by fear of extended and intensified bombing, are accepted and intended aims of our bombing policy. They are not by-products of attempts to hit factories."
If that doesn't qualify as 'terrorism', I'm not certain what would; but he's a deeply un-radical figure, pretty much heading to the office every day to implement the (widely prevailing) logic of "Total War" in the service of his government, a not-exactly-radical line of business.
(I don't particularly mean to pick on the British, relatively staid people who execute what are unambiguously terror tactics aren't especially uncommon, or confined to any particular nation, he just happened to be a good example that I hit on quickly.)