Yep, nothing's permanent. The British Empire fell apart, the USSR split, America nearly split in the civil war, and now the clock is ticking for the USA, China, and the European Union. No one knows which will crumble first, but crumble they surely will. In the modern era it seems difficult to maintain stability for more than a century or two, so both China and the USA are long overdue.
It's interesting to think that we may be headed for a future in which India is the dominant world power, with Australia the last remnant of Western power.
Sergeant Schultz knew everything there was to know.