By Richard Wike, Director of Global Attitudes Research, Pew Research Center

Special to CNN

The recent news from Fallujah and elsewhere in the Middle East and Africa must be pretty encouraging for al Qaeda sympathizers. The Islamic State of Iraq and al-Sham (ISIS), an al Qaeda affiliated group, has a significant presence in the city where the bloodiest battle of the Iraq War took place nearly a decade ago. ISIS and other al Qaeda inspired groups have also met with success on the battlefield in Syria, while extremist groups who embrace both violence and a severe, distorted version of Islam are on the offensive not just in Iraq and Syria, but in Libya, Afghanistan, Nigeria, and elsewhere.

Yet if recent history is any guide, extremists’ current momentum will likely be followed by a strong backlash. After all, when it comes to hearts and minds, al Qaeda and its ilk have repeatedly demonstrated that they have very limited appeal. Indeed, generally speaking, the more people are exposed to extremist violence and al-Qaeda-style rule, the less they like it.

Read more at CNN’s Global Public Square blog