The emergence, and proliferation, of Islamist militant organizations, ranging from the Islamic State of Iraq and Syria (ISIS) and Al-Shabbaab in Somalia, to Boko Haram in Nigeria and other parts of West Africa, has once again demonstrated that political Islam is an important global political issue. It has also highlighted a number of challenging, but increasingly crucial analytical questions: How popular a force is militant Islam, and how is it distinguishable from more conservative and moderate forms of Islamic activism? Does the rise of Islamic militancy across many regions of the Muslim world represent a “clash of civilizations,” or is its emergence a result of locally embedded, but globally linked, economic and social forces? And, finally, given the considerable diversity of socioeconomic formations within Muslim societies when, and under what conditions, do religious rather than ethnic cleavages serve as the most salient source of political identification?