Where is a superpower when you need one?

Many Americans suspect that their country’s relative decline is being met with gloating in other parts of the world — and not just in the dictatorships that have good reason to fear a strong United States. Americans imagine that even many firm friends have long nursed quiet resentments of the rule of their big brother, and that those historic slights mean a certain pleasure is being taken in America’s waning.

Those suspicions aren’t wrong. If you have trouble understanding how even the most ardent ally can also have a younger sibling’s sense of grievance, watch “In the Loop,” the BBC comedy loosely based on the run-up to the 2003 invasion of Iraq.

In one scene, the British prime minister’s enforcer, a character modeled on Alastair Campbell, arrives at the White House for a meeting on the impending war only to discover that his counterpart is a 22-year-old. His poetically obscene response is classic Campbell, and an illustration of why even some loyal Brits might not be totally dismayed by the humbling of the superpower.

Although the schadenfreude is real, it is swiftly being replaced by an even more powerful emotion — nostalgia. From Berlin to Benghazi, it is becoming increasingly clear that in a crisis it is awfully handy to have a superpower around.

That sentiment is being felt most strongly this week in Europe. The Americans missed most of all across the Atlantic are American consumers — if only they were buying as voraciously as they did before the 2008 crisis and the U.S. economy was playing its old role as consumption engine for the world, Europe’s financial woes would be a lot less severe.