Remember the global financial crisis, triggered six years ago when billions of dollars of dodgy loans - doled out by banks to subprime borrowers and then resold numerous times on international debt markets - began to unravel and default? Stock markets plunged, banks collapsed and the entire global financial system teetered on the brink of catastrophe. Well a similarly chilling economic scenario could be set off by the current collapse in oil prices. Based on recent stress tests of subprime borrowers in the energy sector in the US produced by Deutsche Bank, should the price of US crude fall by...