I was not talking about civilizations but countries with their current institutions. The current incarnation of China was born in the late 70s, when Deng Xiaop

I was not talking about civilizations but countries with their current institutions. The current incarnation of China was born in the late 70s, when Deng Xiaoping managed to consolidate power after generations of chaos. Most major European countries collapsed at least once in the 20th century. The UK was the main exception, but it also fell from a global superpower to a regional power. In contrast, the US still has the same centuries-old constitution, and it hasn't faced a serious challenge to its continued existence since the Civil War.