SINGAPORE — Festooned with red lanterns and banners bearing auspicious messages, the ornate façade of the 19th-century Thian Hock Keng temple in downtown Singapore seems even more flamboyant than usual. The temple is readying itself for its busiest time of the year: Over the next few weeks thousands of worshipers will make offerings and pray for a favorable Chinese New Year. It’s a time when even the least conscientious of temple-goers, like me, make an effort to maintain the customs that link them to their heritage.

Such a classically Chinese setting may seem an unlikely place to start questioning one’s traditions, but to be in Singapore today means to challenge conventional ideas of Chineseness. As China rises on the world stage, it is exporting its notions of Chinese culture and ethnicity, creating new tensions within Chinese communities abroad. In Singapore, Chinese people used to be called zhongguo ren or hua ren interchangeably: The small distinction between the two terms — the former relating to people with Chinese nationality or born in China; the latter to anyone ethnically and culturally Chinese — was considered artificial. But subtle divisions of this kind have now become the crux of what it means to be Chinese here.

Three-quarters of Singapore’s people are ethnically Chinese, most descendants of Hokkien-speaking immigrants from Fujian Province in southern China who came to the island in the first half of the 19th century, when it was a British settlement. Malays and Indians, both indigenous and immigrants who also arrived in the 19th century, have long formed important communities in the territory. But it is the predominance of the ethnic Chinese that was crucial to Singapore’s formation in the first place.

In 1965, Singapore broke off from freshly independent Malaysia as a direct result of bitter disputes over the preservation of rights for ethnic Chinese and other minorities in the new Malay-dominated nation. (The two territories previously were part of a loose federation.) Today, this tiny Chinese enclave has a G.D.P. per capita about five times that of its far larger, resource-rich neighbor.