Why civilizations suddenly collapse

For the past couple of centuries historians have been pondering the question of why once-successful civilizations collapse--often with startling speed.

Wretchard at Pajamas Media suggests the reason is that the leaders of nations on the brink of disaster don't realize their civilization is in trouble, so they don't change the policies causing the problems. They're wedded to what they think is a winning formula —at least, it's certainly the formula that brought them to success — so it never occurs to them to do anything different.

Thus when an existential crisis arrives, they continue doing the same things that brought them to the brink of collapse--and are surprised when things don't get better.

The leaders of the European Union seem to be caught in this. They can't imagine the possibility that their policies are flawed; it's literally unthinkable. So all of their responses are merely variations of the known ‘winning formula.’

Commenter JMH at Wretchard's has a slightly different take: [I've edited a bit]

Some of our so-called "elites" surely see the doom coming. The problem is, the only way to avoid it would be to stop doing the things they have always been rewarded for. This would mean rejecting their old policies and boldly charting a new course.

They can’t bring themselves to do that.

Subconsciously they know they’re more lucky than good. They don’t have enough confidence to throw it all away and start from scratch. They didn’t start from scratch before – we’re not dealing with a first-generation elite who succeeded by their own efforts. We’re dealing with follow-ons--people who have weaseled their way into inheriting the manson someone else built.
They know how to weasel. But they have no idea how to build--and that truth must terrify them, even if only grasped unconsciously.

They figure the odds of coming through a paradigm shift on top of the heap aren’t any better than avoiding the doom they see coming. So, perhaps subconsciously, they deny the doom. They see it, but pretend not to. Because to admit it would mean having to make tough decisions, work hard, and likely lose their power and position.

They’d rather fly the plane into the ground than let someone else take the controls.

Wow.