In terms of thinning out the nutter population it hasn't worked at all, they are still being radicalised at home in significant numbers, picking up combat experience by the bucket load (yes first in Iraq but then in Yemen and Syria where they don't have legions of western JSOC ninjas breathing down their necks) and without doubt pose the single largest, potentially existential threat to the kingdom. You reap what you so and there is a whirlwind heading Saudi's way when the King falls of his perch.
2003-2014 was the opening act IMHO, the main event is just getting started and no country in the region will come through it untouched by the fallout.
What do you mean by the last part?