Oil reversed declines after the U.S. announced it would send air defense systems and troops to Saudi Arabia following attacks on the country’s oil production facilities that shut half of its output.

Futures erased losses to settle little changed in New York after earlier falling as much as 1.9%. The Pentagon will send an additional Patriot missile battery, four radar and 200 more personnel to Saudi Arabia, extending the region’s air defense coverage in the wake of the Sept. 14 aerial assault. The attack has been blamed on Iran, and any military response risks destabilizing a region that is home to some of the world’s largest oil producers.

“Prices rose on fears that this means increased likelihood of military action and possible destabilization of the region and supply,” said Bart Melek, head of global commodities strategies at TD Securities in Toronto.

Oil prices dipped earlier on news that Saudi Arabia is recovering more quickly than expected from the aerial assaults to its infrastructure. State-owned Saudi Aramco is a week ahead of its repair schedule after the attacks more than a week ago, and have lifted daily output above 8 million barrels, according to people with knowledge of the matter.

“The market has been weighed down by much-sooner-than-expected Saudi oil output and the start of U.S. refining maintenance season,” said Andy Lipow, president of Lipow Oil Associates LLC in Houston.

West Texas Intermediate for November delivery settled down 8 cents at $56.41 a barrel on the New York Mercantile Exchange.

Brent for the same month rose 35 cents to $62.74 on the ICE Futures Europe Exchange and traded at a $6.33 premium to WTI.

Iran announced it has raised nuclear capacity in contravention of its 2015 agreement with world powers, further stokinf Mideast tensions. The announcement is “an elevation of geopolitical risk” that could lead to a conflict in the Straight Hormuz, Melek said, referring to the world’s most important oil choke point.