Americans’ penchant for paranoia and violence? As exceptional as we like to think we are, we’re not the only human beings in existence, Dave. What we’re talking about here is a universal human reaction to extreme scarcity, and a universal human response to intense competition for survival. In circumstances like that, leaders are simply the dudes who brought in the last food and water; “fascistic” is kind of beside the point. And any civil society, robust or otherwise, will break down quickly when its infrastructure collapses. New Orleans right after Katrina offered us a G-rated sneak-preview of that phenomenon.
New York after 9/11 is a bad analogy, though. In post-power (sub)urbia it’ll be more like “Escape from New York.” There won’t be a mere few minutes of terror and destruction, followed by a coming together in numbed relief. There’ll be an endless stream of daily battles to secure just enough food and water and shelter ’til tomorrow, especially during the winter months. So yeah, an every-person-for-self strategy will be typical, and probably more effective, too.
But this isn’t lazy “apocalyptic thinking,” which itself is a lazy man’s epithet — “apocalyptic” meaning nothing more than an uncovering or a disclosure, except when it’s employed as a rhetorical device to evoke Biblical images of end times, which is why you describe it as “public prognostications” and “prophecies,” I suppose, for similar emotional effect, not to mention easier dismissal. But no, it’s just neutral mathematics.
(How you came to know that prophecies have some potential for self-fulfillment would be a much more interesting and informative post than this one, though!)
And since you’re already (or still) of an “us” vs. “them” mentality, and you’re hopeful that “we” are prevailing, I’d say you’re about as well prepared for this publicly prognosticated scenario as anyone! :-)