[pocksuppet]

Countries collapse very often. The land, cities, and people remain, and organize into new countries. Democracy was meant to pre-empt this with a regular controlled collapse and handover, like a controlled forest burn, but a democracy itself can also collapse.

[Muromec]

Mind giving two examples that are attributable to questionable policy choices and not the usual empire lifecycle?

[pocksuppet]

The usual empire lifecycle is caused by questionable policy choices.