It triggers in me one of those occasions for updating the evolving philosophy of Ed.
The history of the 20th century was of course dominated by the rise and fall of communism. Even events such as the rise of Hitler and the eclipse of the Shah of Iran by Ayatollah Khomenei can be neatly seen as reactions to the rise and fall respectively of Soviet communism.
With the final collapse of Communism in 1989 came a kind of phony peace, where threats were evolving more quickly from their relatively unevolved forms once the settlement of the world order was freer and the USA refrained from asserting its authority. Events such as those transpiring in Rwanda, Somalia, and Bosnia were unusual in that they weren't fallout from some intractable international stasis owing to disagreements among powers, but rather the result of local factions struggling to assert themselves when no great power was really interested.
The lack of colonial policing in a world used to it has resulted in the evolution of threat into philosophy, into religion, and back into more violent threat once more.
The US, partially in Afghanistan, and wholly in Iraq, strode boldly back into the field of disorder. As Melanie points out, colonial policing is not a linear game: you attack one party partly to get to others or to achieve wider objectives. The question is, do the Americans understand that Iraq is the route to Iran? It's only geography, after all.