Yemen has the highest guns-per-capita ratio in the world after the US. Tribesmen – some of whom have camped out in Sanaa's Tahrir Square – are widely said to have grenades, mortars, and even a rare tank.
A flurry of recent reports have described cleric Anwar al-Awlaki as a key leader of Al Qaeda in Yemen. But the portrayals may be exaggerated.
US interest in the case of Sharif Mobley, who was set to be tried today, illustrates broader concern about American Muslims going abroad to train with militants.
Suspected in the kidnapping of nine foreigners last week, the militant group appears to be gaining momentum – thanks in part to weak central government.