Thus, one conclusion from academic studies of civil wars that directly applies to ending terrorist campaigns is that, when spoiler violence occurs, it matters whether or not outside parties label it illegitimate.155 Whether states support the cause of the incumbent or challenger side, absent or ambiguous responses to terrorist attacks carried out by spoilers augment their effectiveness and undermine negotiations. When the response is outrage at the attackers themselves, on the other hand, spoilers may not spoil the talks at all.
