Indeed, empires are complex systems, with many factors influencing one another and also the final outcome. While we tend to apply a sort of linear causation, which is equally employed to explain the rise of great powers as well as their decline, it is not the way the real world works. Professor Ferguson refers in context to the current prognosis about the decline of American empire, and contends that this may happen not in a series of logical steps as we seem to expect it, but with an abrupt, chaotic bang [or, whimper, indeed].
However, except for Professor Ferguson's rather obvious central argument - that hindsight may be an exact science but it isn't very useful - one may question whether it is pointless, or wrong, as Professor Ferguson argues, to try to discover a pattern in imperial decline. This is because all social decline is inevitably a rather disruptive and painful occasion. While the distance of hindsight may make it look orderly, logical and even desirable, no one would want to opt to live through the times of breaking of empires themselves.
Take, for example, Thomas Cole's paintings of The Course of The Empire, a rather neat, logical sequencing of rise, decline and fall, which lies at the centre of Professor Ferguson's essay. While Cole's paintings, seen in sequence, represent a rather abrupt movement from an idyllic community to consumptive decline, but these still visualizes a linear sequence, precisely what Professor Ferguson believes is not possible in real life. Counter intuitive as it may be, those paintings can only be created with the advantage of hindsight. Thomas Cole, with his penchant for creating visual narratives, was trying to tell the tales of Rome; his paintings do not seem to imagine the ruinous bureaucracy that undid the Soviet Union or the financial crisis that drew the curtain of sorts on the British empire.
One may argue that precisely that is the point Professor Ferguson is trying to make - empires decline unexpectedly and the decay comes from varied, unpredictable and therefore uncontrollable sources. In context, Jared Diamond's environmental consumption sounds too simplistic, as well as Paul Kennedy's theorem of self-induced financial ruins: Each of these theories seem to be a product of their respective times. That way, all such theories may be construed as an attempt to fashion history to meet a current intellectual paradigm.
However, on a closer examination, the point of the essay is not to establish a meta-theory of imperial decline, which combines all the various strands of thought, but to forward an absence of theory, an argument that imperial declines are too complex to understand and to predict. Professor Ferguson seems to remain true to the end of history thinking, and seems to argue that historical narratives are mere ex post construction based on available theory, and no useful prediction or policy could come of such exercises. In short, he is not talking about the chaotic and abrupt end of the American empire; his point is precisely the opposite, on the futility of engaging in such a discussion.
But, can it be argued that this is also the precise reason why empires fail, because, each, in its own way, believe that they have reached the end of history? Despite Thomas Cole's paintings and dramatic stories of the end of Roman, Mughal or the Ming empires, and notwithstanding the criticism of 'narrative fallacy', it is possible to see that most empires decline from inside. Or, more correctly, while all organizational systems decline inevitably, most of the times, such systems can engineer their own regeneration. The narrative of decline that we seem to be affixed to are those of permanent decline - where the regenerative factors are feeble and can not reverse the inevitability of decay - which, if one thinks closely, are entwined to the belief of the end of history.
So, that way, end of history is not about eternal progress, but it is the end of progress; because progress exists only in context of stagnation. Complexity, while it can not be ruled away, is an essential grain of all human life, but that may not lead away our imagination and turn us into fatalistic zombies. One must remember that we, as individuals and members of societies, are active players of the complex world. Empires decline precisely when a populace loses the intent to actively script their future; one may argue about complexity, but this may be the lazy way to pass the buck.
Empires are not necessarily the brightest things human beings are capable of creating, but they have dominated the political and social life of most people as far as history goes; hence, the rise, decline and fall of empires represent instructive stories in human organization and progress. While a considerable effort was devoted to the fall of the empires, it is equally important to examine the 'regeneration' of empires, Mughals under Akbar, Manchus in China, Victorian Britain, or the Post-Colonial America [which combined the industrial muscle with the invention of soft power] - those which did not write off the history, but actively engaged to reshape it, and themselves, from within.