You mean that dark and backwards regime we put in power? You do realize we are the ones that caused their regime to rise up as it did. Hell we even bragged about killing their leaders to other world powers to keep them "in check" because they were beginning to become a sovereign nation. We all know the West, and the USSR didn't enjoy it when countries tried to assert themselves post WWII.
Wahhabism is the main export of Saudi and its radical roots are the problems we are dealing with today. Not to mention the state sanction spending for promoting this particular sect of Radical Islam. I'd highly suggest reading up more on it.
I'd start here
Wahhabism and go on from there. The only reason Iran was labeled for terrorism was their support from the USSR during the late 70s and 80s. The exact same reason Cuba was listed as well.
You'd think some 40+ years later we'd know better than to assume just because someone wants to be friends with another country that we disagree with their government does not make them a terrorist.