The fact is that 'shadow of the apocalypse' has always been there and is still there. Civilization is merely an agreement among individuals to ignore the possibility of it.

What Americans are finding out is that there are individuals who are willing to disregard the notion of civilization. These individuals are willing to break the agreement for, well, some reason. Timothy McVeigh basically warned us of this. (Of course, there are some individuals that can't comprehend that the agreement exists at all - but that's another story.)

Wealth, peace and secularism have, for a few brief years, concealed from us the customary presence of the abyss. But now it is back in full view.

Bzzt. The abyss was always there, irregardless of wealth, peace or secularism. We might have ignored it, but it did exist.