I think that much of this answer is going to be dependent on the idea of what defines "radical." If we are examining the idea of "radical" as one that fundamentally changes the way revolution is viewed, the French is more radical than the American change because it shows the dark side of revolutionary change. The American Revolution presented how a collective effort can be inspirational, how change can transform reality into something better than what is in the hopes of what can be. This was not the case in the French Revolution, where the Reign of Terror was almost as bad, if not outright worse in its hypocrisy, than the Status Quo of the French Monarchy. The culmination of the revolution in Napoleon's ascendancy into power is radical in that it repudiates the initial revolutionary spirit, something that the American Revolution, even in its darkest moments of struggle, never did. The French Revolution can be considered more radical than the American Revolution because it fostered a fundamentally new way of seeing revolutionary fervor as not one of "pure bliss," but rather one that has the potential for devolution and stressing the distinction that declaring independence and getting it are two different realities.