Iraq cannot afford to pay millions of workers and pensioners. Mexico’s grand plans to develop the country have been thrown into disarray. Ecuador is cutting government salaries, and Venezuela is on life support. Nigeria is seeking a nearly $7 billion emergency loan.

The coronavirus pandemic and the collapse in oil prices it has caused have created a monstrous calamity for countries heavily reliant on oil production for their economic survival, and forced others to change policies that no longer make economic sense.

While Russia, Saudi Arabia and the United States — the biggest oil producers — have large financial cushions, the precipitous drop in demand because billions of people have been forced to stay home has upended everything. It was a possibility even veteran industry experts did not foresee.

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“No one imagined a crisis of this scope. This was in no scenario,” said Daniel Yergin, an expert on global energy and vice chairman of IHS Markit, a research firm.