An Afghanistan-based branch of the Salafi jihadist Islamic State group has in the past year recruited Tajik and other Central Asian militants to build to a size and sophistication that give it “the ability to project a threat into the region and beyond”, according to a report submitted to the UN Security Council. The analysis has aroused new interest given how on March 22 Russia suffered its worst terrorist attack in two decades, with the armed assault on concert-goers at Crocus City concert hall on the edge of Moscow causing a death toll of at least 137. On March 24, four suspects, officially…