The biggest threat to Vladimir Putin’s grip on Russia in his almost quarter-century of rule has huge implications for the oil market. But dissecting the precise impact of last weekend’s mercenary mutiny is difficult, according to Bloomberg Opinion columnist Javier Blas. On this week’s In the City, Blas explains the bearish case and the bullish case. He also on his conversations with the central banking community in Sintra, Portugal at the ECB Forum.