My dog in this fight exists somewhere between the two sides (the mental loopholes the one side jumps through to put Garlean aggression on the same level as other grey aspects of this game's world are almost comical; on the other hand, I don't think it's fair to reduce them to black-and-white-capital-E-Evil either, and I'm very eager to witness their civilian society and want to meet moderate elements as well), but terrorism is specifically targeting a civilian population to undermine an opposing side through the use of fear. Hien is not doing this - Garlean civilians don't live in Doma, and nothing he's doing is targeting Doman civilians, so no. No, it's not sponsoring terrorism. It's fighting back against an invasive military state. He has just as much right to do that as Garlemald had to seize his land in the first place, at the VERY least.