Two failed terror attacks in Europe remind us that terror strikes don’t always work. However, even when the attack is successful, terror organizations rarely accomplish the military, political, economic, or social goals they set out to achieve.

In Belgium, a terrorist tried to set off a bomb in a railway station. The explosion was small, not having the effect the attacker desired. He was subsequently shot and killed by soldiers.  It just so happens that another would-be terrorist rammed his car into a police vehicle in France. The driver died, but was unable to kill any law enforcement officials.

Both cases reminded us that terror attacks don’t work, and often fail more than you would think, because such unsuccessful attacks get a lot less press. But more importantly, even when their terror strikes are successful, it doesn’t mean that they accomplish their real goals.

On the day terrorists were engaging in their knife attack on the London Bridge, I was presenting undergraduate research we had done about whether terrorism actually works, at a religion conference outside of Atlanta. It was an eerie reminder of two years ago, when terrorists attacked in Paris the day that my students and I presented on lone wolf terrorism at a political science conference in Savannah.

Actually, the results that more than 40 students and I found were quite illuminating.  We looked at 90 groups. Of these, half practiced terrorism, and half did not. Students across two of my classes signed up to study these groups. They researched what these groups were trying to accomplish. What was their objective or objectives? Then they analyzed the tactics these groups used, and whether they accomplished their goals, like having a separate homeland, control of a government, the expulsion of foreign occupiers, changing a government policy, etc.

Some were pretty well known, like ISIS. Others were more obscure, like the Carnation Revolution or the Cedar Revolution. I tried to pair the groups up, having one group practicing terrorism (like ETA, the Spanish Basques group) and one not practicing terrorism (like the Spanish Catalonians).

We found that among the terror groups, only 13.3 percent actually accomplished their goals. For those not using terrorism, such groups accomplished their goals 57.8 percent of the time.

Don’t get me wrong. Terrorists are able to kill a lot of people. And they get a lot more attention. I found that ISIS got 233 million hits on Google, while the Carnation Revolution (148,000 Google hits) and the Cedar Revolution (58,000) barely get any attention. Yet the Carnation Revolution forced the Portuguese military from power peacefully, while the Lebanese largely refrained from violence in expelling the Syrians from their country after decades of foreign rule during the Cedar Revolution. Meanwhile, despite the deaths and all the publicity from attacks in London and Paris, ISIS is no closer to the establishment of an Islamic Caliphate or forcing Britain to give in to their demands, while both of the other revolutions succeeded in a much shorter period of time. In preparing for the religion conference, I found a cartoon where a terrorist is trying to water a dying tree with a can that only pours out bullets, asking himself “Why doesn’t it grow?” That’s because it’s hard to give life to something with only the instruments of death.

John A. Tures is a professor of political science at LaGrange College in LaGrange, Ga.  He can be reached at jtures@lagrange.edu.

His Twitter account is JohnTures2.  His co-researchers  can be found listed online.

on this project include Alex Gaba, Austin Brown, Austin Jones, Braden Shealy, Brandon Collins, Breckin McCoy, C. J. Lord, Dalton VanEgmond, Damir Rosencrants, Daniel Garrett, Davis Clark, Elijah Brague, Emily  Barrs, Erik Moran, Grant Perry, Hank Harrison, Jackson Patrick, Jaida Rashad, James Poropatic, Jeremy Maddox, John Williamson, Jose Almanza, Katelynn Dixon, Keaton Coates, Mitchell Corley, Noah Clipper, Rachael Pike, Richard Howell, Riley Densmore, Robert Allen, Salman Rahim, Seth Golden, Stephen Coelho, Sydney Aronson, Toni Ball, Tripp Bridges, Wesley Dismuke, Wesley Hermonstine, Will Wooten and Zach English.