Europe’s oil industry is once again generating cash even as crude languishes at half the price of three years ago. Yet companies remain vulnerable to a renewed downturn. The region’s top three — Royal Dutch Shell Plc, Total SA and BP Plc — can now cover spending from cash flow with oil at $50 a barrel. But BP predicts prices will drop this year, while Shell talks of a “ lower forever” view. A fresh slump could put dividends at risk, and investors know it. Energy stocks are the worst performers in the MSCI World Index this year, with the 89 companies in the industry losing more than $146 billion in market value. High dividend yields — a signal that shareholders fear a cut in payouts — […]