In short, no. “The disadvantages of terrorism generally outweigh its advantages,” Fortna writes in a new paper, “Do Terrorists Win? Rebels’ Use of Terrorism and Civil War Outcomes.” Defining victory on a scale that begins with total defeat, includes quietly ending and stalemate as negative outcomes, and negotiated settlement or outright victory as positive outcomes, Fortna finds that terror “is a cheap way to inflict pain on the other side, and terrorist groups are hard to eliminate completely, but it is useless for taking or holding territory.”
Studying terror requires defining it. Fortna considers 104 rebel groups fighting in large civil wars, all of them since 1989. Among them, groups that engage in systematic, indiscriminate violence against civilian targets for political purposes qualify as terrorist. The time limitation offers a more useful picture of the current landscape of terrorism, cutting off the examples of rebel movements—many using terror—that successfully gained independence in the post-colonial era. (Think Algeria.)
The results of the 104 cases are striking. Non-terrorist movements are far more likely to win a settlement or an outright victory, while the terror groups tend to lose, fizzle out, or drag on. “Of the groups examined here, none of those that deliberately killed large numbers of civilians through terrorist attacks won its right outright,” Fortna writes.