Just one damn thing after another

Pete's comment in my Gore post speculates on another historical accident -- the near-election of Henry Clay as President in 1844, instead of James Polk, meaning there would likely have been no Mexican American war, possibly no Civil War, etc etc.
This brings up the whole fascinating discussion of Alternative History. Someone once described history as "just one damn thing after another". Once we all get over the childish belief that god or the pope or the telephone company is actually running things and therefore everything that happens is by fate or plan, then we can realize that the specific sequence of things we call history was not inevitable at all. And then we can analyze the extent to which our history was either accidental or purposeful, for the clues it may provide as to how our future can be directed.
For example, it could be argued that Churchill being PM of Britain during WWII was a happy accident of history, resulting from the resignation of King Edward VIII in 1936, who, if he had been king in 1939, might well have been stubborn enough to pick Lord Halifax to form a government instead of Churchill (even King George wanted Halifax but was willing to be disuaded by Chamberlain).
Then again, however, an argument for purposeful direction could also be made, that because Churchill continued to serve in the House of Commons throughout the 20s and 30s, when lesser men might well have quit politics after such a disasterous term as First Lord of the Admiralty during WWI, so therefore Churchill put himself in the right place at the right time to become PM when England needed him most.
When historians look at the first quarter of the 21st Century, I wonder what will be considered an accident, and what might turn out to be purposeful direction.
The main theme, I think, will be the analysis of the decline and fall of the United States as the world's economic and political leader. Whether this will be ascribed to the disasterous outcome of the historical accident of 911 or to the disasterous outcome of the lurking neocons who waiting to seize on such an opportunity to start unwinnable wars will depend, I suppose, on whether it is the Chinese or the Europeans who will be writing this story. History, of course, is always written by the winners.