Step by step, al-Shabaab is being rolled back in Somalia. The al-Qaeda affiliate appears to have been compelled to abandon Kismayo, the last big town under its control. That matters a lot because Kismayo is also a significant port and the extremists were making plenty of money by shipping charcoal and other goods out and weapons in. If they have lost Kismayo, they will have been deprived of perhaps their most important source of revenue. Only a year ago, al-Shabaab controlled almost all of southern Somalia including most of Mogadishu. When I visited last December, they were still clinging to some enclaves of the capital. Today, they have been kicked out of Mogadishu altogether and reduced to a largely rural insurgency. The way in which this has been achieved is interesting. In effect, Somalia has served as the test bed for a new model of intervention. Instead of Western troops doing the fighting as in Iraq and Afghanistan, all the combat operations have been carried out by soldiers from the African Union, drawn principally from the armies of Uganda and Burundi. The West has provided the funding, logistical and intelligence support; the African soldiers have taken on al-Shabaab and beaten them time and again. The capture of Kismayo is further proof that this model works