Looking back through history – hegemons seem to have a propensity to fail. Why is it so?
There is no dearth of theories (I’d rather call them conjectures) in this regard. One set argues that hegemons crumble from within. Military/economic overstretch is blamed. Another hypothesis is ideological overstretch: success breeds hubris, and hubris leads to inevitable doom when the regime’s ideologues come to believe that “We’re an empire now, and when we act, we create our own reality. And while you’re studying that reality—judiciously, as you will—we’ll act again, creating other new realities, which you can study too, and that’s how things will sort out. We’re history’s actors … and you, all of you, will be left to just study what we do”. There would be a third hypothesis – the failure of the hegemon’s elite to secure and sustain its internal legitimacy. This would lead to internal revolt, and eventual collapse. Alternatively, as administrative power is delegated to satraps in the various regions included in the empire,the latter tend to strive for independence and the empire disaggregates. As I’ll deal with the issue of legitimacy in an international setting, I’ll forego a discussion of this hypothesis here.
Common to all these arguments is the eventual collapse from within. The world outside the empire is essentially ignored. The hegemon’s foreign policy, however, may also lead to its downfall, in my view. A hegemon tends to enlarge its empire as long as the expansion’s benefits outweigh the costs. What’s beyond this “economic” border is left to its own devices. As peoples beyond the boundary learn from the hegemon’s political success and profit from cross-border trade the equilibrium of power shifts – often surreptitiously. The periphery strengthens and in the end overwhelms the center. This is how Rome and China succumbed to invasions by their once “barbarian” neighbors.
In a world where conquests no longer apply, as is the case today, the hegemon can only “rule” by creating an international world order suited to its ambitions. Here a new cause for hegemonic failure emerges, one that harks back to the question of legitimacy to which I referred above. Only the setting is international, rather than internal to the empire. This process is playing out under our very nose.
After WWI the US tried to impose a “world order” based on Wilson’s 14 points. It was doomed from the start. The other winners of WWI were too much out for revenge and reparation to accept such “fair” principles. That the principles contradicted each other (e.g. right to self-determination vs. no secession) and were unrealistic did not help. “Wannabe” hegemons sprouted among the losers (and quasi-losers Italy and Japan) on the strength of totalitarian and eutopian ideologies. Three aspiring hegemons were liquidated in WWII; the fourth succumbed to subsequent containment.
The American-led “new world order” after WWII was well received – after all most countries needed US economic assistance. The UN-centered system emerged. Having imposed such a world order, however, the hegemon was faced with the inevitable conundrum of any sovereign – whether to abandon its “right to exception” in favor of playing by the rules of the new order.
From the point of view of states which have to live with a “world order” legitimacy obtains only if and only if the rules apply to all – including the hegemon. For the hegemon then the price it pays for imposing such world order is its eventual loss of control of the evolution as well as the loss of the right of exception. After all, exception is the PC equivalent of hegemonic ambition.
No elite rule can be sustained without political (or religiously motivated) legitimacy. Whether it is a foreign elite in a newly conquered country or a hegemon wanting to rule other nations, they both face the same challenge: how to graft a new order, which lacks traditional legitimacy, onto the extant political reality. In order to achieve some form of legitimacy a conquering elite would have to amalgamate with the conquered or ruled peoples. But in doing so they would lose their identity and thus their means of defense, should an uprising ensue.
Today this quandary plays out even more in international relations, for other countries are far from supine subjects; rather they are active participants and shapers of the world order inaugurated by the hegemon. Is the rule setter subject to the rules it has promulgated? The temptation to retain its “right to exception” is overwhelming, and the US succumbed to it many times. We may find them justified or not on partisan political grounds, but they were essentially unilateral acts grounded in the hegemon’s concern for “stability” – an ambiguous term which covers both world order and the hegemon’s position in it.
In international relations the hegemon has two options: (a) it embraces the order it has created, as imperfect as it is in its own eyes, and in so doing gives this world order legitimacy through a mix of power and example; (b) it retains its “right to exception”, thereby inviting others to claim the same and undermining its own creation. It is the classic case of the better being the enemy of the good.
The hegemon’s failure to choose between these two options will undermine the very world order which sustains the hegemon. This is happening right now in the US. Thomas WRIGHT writes: “Recently, a group of 34 legislators promised to vote against the UN Convention on the Law of The Seas, ensuring that the bill will not be ratified. Their move will make it harder for the United States to continue to build up a rules-based order in the South China Sea. It could also spell the end of treaties as a tool of U.S. national security policy.” He is right – this is self-destructive behavior, and one which forces the US to maintain a military establishment it can no longer afford and which, over time, may even endanger its democratic structures.
So far I’ve highlighted the contradictory position of the hegemon: it is its ambition to create an order to which it will not subject itself. Unless he can successfully bridge the contradiction he’s likely to be swept away by its ability to create or sustain legitimacy. Now I’ll move to the next step. What happens when change sweeps the world and the system of international relations?
 Paul KENNEDY (1989): The rise and fall of great powers. Vintage, New York, His survey of the ebb and flow of power among the major states of Europe from the 16th century, when Europe’s preeminence first took shape, through and beyond the present era, when great power status is devolving again upon the extra-European states, leads him to stress the interrelationships among economic wealth, technological innovation, and the ability of states efficiently to tap their resources for prolonged military preparedness and war making. Those states with the relatively greater ability to maintain a balance of military and economic strength assumed the lead. (From the Library Journal, as quoted in Amazon.com)
 See e.g.: Peter BEINART (2011): The Icarus Syndrome: A History of American Hubris. Harper, New York.
 Attributed to Karl ROVE https://en.wikiquote.org/wiki/Karl_Rove
 Foreign elites that conquered China – the Yuan and the Ch’ing – never managed to sustain their legitimacy and failed, threatening the survival of the Chinese state. The break-up of Caliphates follows similar lines.
 See e.g. Patricia CRONE (2003): Pre-industrial societies. Anatomy of the pre-modern world. OneWorld, Oxford
 Here a (partial) scorecard: attempted to overthrow more than 50 governments, most of which were democratically-elected; attempted to suppress a populist or nationalist movement in 20 countries; interfered in democratic elections in at least 30 countries; dropped bombs on the people of more than 30 countries; attempted to assassinate more than 50 foreign leaders. https://www.buzzfeed.com/provincialelitist/us-military-and-cia-interventions-since-world
 Thomas WRIGHT (2012): Outlaw of the sea. The Senate Republicans’ UNCLOS blunder. Foreign Affairs August 7th.