The assault was swift and sustained: 500 Stormtroopers stood on the Great Wall. X-Wings swooped into Shanghai and Beijing. Lightsabers crackled in theaters across the country.

And millions of moviegoers responded: This again? Who cares?

One after another, “Star Wars” movies have flopped in China, defying efforts to bring one of the most successful franchises in history into a market that has printed money for the heroes, monsters and robots of other films. The latest “Star Wars” movie, “The Rise of Skywalker,” has followed the trend by grossing nearly a billion dollars worldwide and barely breaking $20 million in China.

The episodes that came before it didn’t do much better, for reasons that include history, geopolitics and a distinct lack of the nostalgia that drove viewers in the United States. Thousands of Americans lined up in costumes for each premiere: “The Force Awakens” opened to almost a quarter-billion dollars in the United States in 2015; two years later, “The Last Jedi” made nearly as much; and “The Rise of Skywalker” raked in $177 million in its first few days last month.

In China, those movies opened to $52 million, $28 million and $12 million, respectively.

Chen Tao, who manages China’s biggest fan website, Star Wars Fans China, estimated that China’s fan clubs have fewer than 200 members in all.