Oil fell more than 1 percent on Tuesday as the market hung on tenterhooks over the threat of a military response to attacks on Saudi Arabian crude oil facilities that cut the kingdom’s output in half and sent prices soaring by the most in decades. The Saturday attack heightened uncertainty in a market that had become relatively subdued in recent months due to slowing global growth as the US-China trade war rages. Saudi Arabia is the world’s top oil exporter and has been the supplier of last resort for decades.Brent crude was down 73 cents, or 1.1 percent, at $68.29 a barrel by 0405 GMT, and West Texas Intermediate was down 87 cents, or 1.4 percent, at $62.03 a barrel. Prices surged nearly 20 percent in intraday trading on Monday in response to the attacks, the biggest jump in almost 30 years, before closing around 15 percent higher. Equities and other markets were also pressured on Tuesday.“The question is how long it takes for the supply to get back online,” said Esty Dwek, head of global market strategy at Natixis Investment Managers. “However, the (geopolitical) risk premium … which has been basically ignored by markets in favor of growth worries in recent months, is likely to be priced in going forward,” she said.A gauge of oil-market volatility on Monday rose to the highest level since December of last year, and trading activity showed investors expect higher prices in coming months. Japan said on Tuesday it would consider a coordinated release of oil reserves if necessary.US President Donald Trump said on Monday it looked like Iran was behind attacks on the Saudi oil facilities but stressed he did not want to go to war. Tehran has rejected the charges that it was behind the drone strikes.Relations between the United States and Iran have deteriorated since Trump pulled out of the Iran nuclear accord last year and reimposed sanctions on its oil exports.Washington also wants to pressure Tehran to end its support of regional proxy forces, including in Yemen where Saudi forces have been fighting Iran-backed Houthis for four years.“With the US ‘locked and loaded’ awaiting signs from Saudi Arabia that Iran was involved, tensions in the Middle East could get worse before they get better. Under these circumstances, the price of oil could remain elevated for some time yet,” City Index analyst Fiona Cincotta said.