This report analyzes the U.S. and allied campaign against the al Qa'ida-linked terrorist group al Shabaab in Somalia, examines what steps have been most successful against the group, and identifies potential recommendations. It concludes that, while al Shabaab was weakened between 2011 and 2016, the group could resurge if urgent steps are not taken to address the political, economic, and governance challenges at the heart of the conflict.