The Combating Terrorism Center at West Point published in February 2014 a special issue of CTC Sentinel that includes two articles on al-Shabaab.
The first article is titled "Al-Shabaab's Capabilities Post-Westgate" by Ken Menkhaus, professor of political science at Davidson College. He concludes that al-Shabaab today is both weaker and more dangerous and unconstrained than in the past. In the short term, this is bad news for Kenya, Ethiopia, the Somali government and people, and international actors operating in Somalia. In the longer term, however, al-Shabaab's downward trajectory since 2009 shows few signs of reversal, at least inside Somalia. Additional losses of top leaders could lead to a quick unraveling of the group, at which point the chief security threat will be the residual Amniyat network, which will retain the capacity for extortion and political violence.
The second article is titled "An In-Depth Look at Al-Shabaab's Internal Divisions" by Stig Jarle Hansen, associate professor at the Norwegian University of Life Sciences. He concludes that al-Shabaab will likely continue to attack countries that have deployed forces in Somalia. Al-Shabaab's biggest danger to the West is most likely through potential logistics support for other al-Qaeda units, its indoctrination of Somalis into al-Qaeda's ideology, and its growing reach in African countries.