Everyone knows that the world economy is important in forecasting future conflicts, and if it tanks, the eurasian powers that are hostile to us will move against our allies in the region and us.
They are already doing it. But you are right, it will accelerate the process immensely. I'm surprised how many people want the dollar to fall. Don't they realize how much power we will lose if the dollar, as the reserve currency of choice, begins to give way to the Euro? Not only will it have massive international economic implications, but it we reduce our geopolitical clout as well. We need to save the dollar by bringing it back on the gold standard. Here's a good article to get us thinking in the right direction (read the whole thing...it's worth it):
The Case for a Genuine Gold Dollar
http://www.freerepublic.com/focus/f-bloggers/1696147/posts?page=15