The oil markets have plenty of reasons to be spooked. Political chaos and violence are keeping 3.5 million barrels of daily oil production off the market, according to estimates by Citigroup. With tensions heating up over Ukraine, pressure is building for Western countries to impose Iran-style sanctions on Russia, the world's largest oil producer. The oil markets remain placid because almost all the oil production lost over the past few years has been replaced by the US shale boom and increased Canadian production. US shale oil production started to rise quickly in early 2011, right as the Arab Spring was kicking off. It's hard to overstate the impact that rising US oil output has had on global energy trade. US crude stockpiles are near a record high, causing traders to cut their bullish bets on the futures market.