With three terrorist attacks against the homeland over the last year that trace back, at least partly, to Yemen, this recent report by Richard Fontaine and Andrew Exum at the Center for a New American Security is a must-read. Fontaine until recently was Senator John McCain's foreign policy adviser and traveled with McCain to Yemen in August. AEI's Chris Harnisch and Frederick Kagan have also published a report on the attack titled "Christmas Day Airline Bombing: Yemen and al Qaeda Context." Check it out.