Costs – Security for costs. The judge had erred in law by concluding that, notwithstanding that there had been a real risk of non-enforcement in Russia, the level of security for costs should be reduced by the application of a sliding scale of risk. The Court of Appeal, Civil Division, in allowing the defendants' appeal, held that, once it had been established that there were substantial obstacles sufficient to create a real risk of non-enforcement, the starting point was that the defendants should have security for the entirety of the costs and there was no room for discounting the security figure by grading the risk using a sliding scale approach.