The looming issue of global over-capacity has been further complicated by the sudden return to the market of light, sweet Libyan crude. Exports from Es Sider have returned to levels of around 800,000 bpd over the last month, adding to the pressure on Brent. In the background is the surge in US shale oil production and the mounting pressure on President Barack Obama to lift the US crude export ban that has been in place since the 1970s to guarantee America’s energy security.