Oakley you keep quoting the Fourth Turning as an authoritative source. It ain't. It's more Jungian Tarot than it is a serious academic work. Demographics often is destiny, but this doesn't mean the astrological signs Strauss and Howe assign to various so-called generations have any validity in the real world.
Serious civil disturbance is far more likely to occur in societies that have a fairly young population. Hence the Arab Spring--Egypt's median age is 24, Syria's is 22. In the US the median age is 37. In the UK and France it's 40, and Germany's is a whopping 45, as is Japan's. This is your demographic destiny.
The US had our cultural revolution back in the '60s and early '70s when the population was much younger (~28) due to an unusual demographic bubble. The demographics of the US today would suggest to me that violent political revolution is exceptionally improbable, despite the incessant squabbling of our political class.
Not to mention that our cultural and economic geography has changed tremendously since the mid-19th century, The US is far more culturally, economically, and politically integrated than it was in the 1850s. We are bound together by a powerful federal government, national media (radio, TV, movies, internet), a high degree of state-to-state mobility, the interstate highway system, national rail systems, national chain stores, regional power grids, national banks, etc., etc., etc.
Of course, much of this integration is thanks to cheap energy and other abundant natural resources. As those diminish we'll likely see a disintegration of the United States that will eventually result in the dissolution of the union. But this will take many decades, centuries perhaps. And I wouldn't count on the dissolution being the result of a violent revolution. Not that we'll be able to find out, we'll all be long dead when it happens.
As for Europe, I don't know the details about their situation, so I can't say. I've been to Europe a few times, they are divided much more strikingly along ethno-linguistic lines than the US is. And the EU is a much looser political structure than the US fedgov. It wouldn't surprise me to see the EU dissolve, but I doubt very much it will result in bloodshed.
Here's a map to ponder:
Youth (15-24) Population Shares of Total Population in 2010
A garden will make your rations go further.