British columnist Seumas Milne (in his latest, just-published book The Revenge of History: The Battle for the 21st Century) argues that in the late summer of 2008, two events in quick succession signaled the end of the New World Order (a unipolar world based on the uncontested US military supremacy and western economic dominance) inaugurated by George Bush Senior in 1990.
These two events were: the defeat of the US client state of Georgia in a brief but bloody war with Russia over South Ossetia –which put an end to two decades of uncontested US power— and, three weeks later (on 15 September), the collapse of America's fourth-largest investment bank, Lehman Brothers (“a sort of right-wing equivalent to the fall of the Berlin wall”, according to historian Eric Hobsbawm) –which engulfed the western world in its deepest economic crisis since the 1930s.
In short: after a decade of continuous warfare, the US succeeded in exposing the limits, rather than the extent, of its military power; on the other hand, the neoliberal capitalist model that had reigned supreme for a generation crashed (and was only rescued from total disaster by the greatest state intervention in history).