Question for Arnold: How bad would things in Europe have to get to count as a "collapse"? Even if their per-capita GDP fell by 50%, they'd still be doing very well by world and historical standards. And it's hard to see even that as "a real possibility."
In any case, Arnold remains far from Tyler's straw man. Arnold's "verge" seems to be about 50-100 years away. (Am I judging correctly, Arnold?) In ordinary political use, though, I'd say a "verge" is more like 2-5 years.