The Rwanda-backed M23 rebels – M23 for 23 March 2009, when a peace deal was signed with Congo’s president, Joseph Kabila – attacked the city of Goma, in the east of the Democratic Republic of the Congo (DRC), on 17 November, trouncing the Congolese army in less than three days. Twelve days later they withdrew. But they have not melted back into the hills of Northern Kivu from where they launched the assault. They have put a ring around Goma and are staying put until the power-sharing agreement for which they’re named is renegotiated in their favour. Meanwhile, Goma, a border town of one million people, resembles Berlin in the Cold War, an island linked to the west by an air bridge.