Libya’s political crisis is threatening to return the OPEC member’s oil production to the chaos that plagued it for years after the toppling of dictator Moammar Gadhafi.

The North African nation’s crude output was slashed in half last week as authorities in the east shuttered more than 500,000 barrels a day amid a fight with the Tripoli-based government for control of the central bank. All the nation’s eastern export terminals closed on Thursday.

The disruption could swell to 1 million barrels a day, according to consultants Rapidan Energy Group. That would amount to roughly 1% of global supply. It would also mark a major fracturing of a 2021 political arrangement brokered by the United Nations to reconcile the two rival camps.