Empires End From Elite-Driven Wars and Overstretch

Empires statistically always end, usually from a series of unpopular wars pursued for elite interests leading to miscalculation, plus overstretch, elite capture, and a misreading of what made the society work; the collapse comes gradually then all at once (the British Empire took ~40 years and few realized it was ending), so America's eventual decline—likely amid Chinese or Indian competition—will be slow and hard to perceive in real time.