AMMAN, Jordan — Jordan had seen scores of antigovernment protests, but nothing like this: For three straight nights last week, mobs angered over rising fuel prices rampaged through a half-dozen cities, torching cars and police stations and rekindling fears that one of America’s closest Arab allies in the Middle East was foundering.

Then, almost as suddenly, the storm appeared to pass. Weekend demonstrations in Amman drew smaller crowds, and by Monday, officials were quietly celebrating signs of normality after the worst unrest here in 15 years.