UNTIL recently the Abraaj Group, a private-equity firm based in Dubai, was riding high. It was one of just a few such firms focused on emerging markets, and a darling of “impact investors”, who seek social or environmental returns, not just financial ones. Assets under management of $13.6bn made it the largest private-equity firm in the Middle East, and the 42nd-largest globally in 2017. Its Pakistani founder and boss, Arif Naqvi, a regular at Davos and a patron of the arts, had won awards for philanthropy.