In 2003, a rift erupted between IAIA's old guard -- who were seeking to establish a new political front -- and its younger members (Al-Shabaab, which means "the youth"), who were seeking to establish fundamental Islamic rule.
That led the latter to ally with a group of sharia courts -- the Islamic Courts Union (ICU) -- that was seeking to impose order over a landscape marked by feuding warlords in the capital city.
Working together, the ICU and Al-Shabaab succeeded in 2006 in gaining control of Mogadishu. That sparked fears in neighboring Ethiopia that violence would spill over there, according to the Council on Foreign Relations.
Those fears -- combined with a request from Somalia's transitional government -- led Ethiopian forces to enter Somalia in December 2006 and to remove the ICU from power.
That move proved to be a turning point, one that radicalized Al-Shabaab, which attacked Ethiopian forces and gained control of parts of central and southern Somalia, according to a 2011 case study by Rob Wise, who was then with the Counterterrorism Program at the Center for Strategic and International Studies.
