Over 1,500 years ago, Rome fell to Germanic tribes once seen by the empire as a mere nuisance. While the fall of the Roman Empire has spawned hundreds of theories and comparisons to modern troubles, this much at least is clear: no superpower is immortal. Americans seem unable to conceive of a world in which we are not supreme, but we are slowly getting the message.

Much like the US today, Rome was once the world's sole superpower. An empire whose influence spanned across the entire Mediterranean and into Asia and Africa, few civilisations in history can rival the sheer breadth of Roman influence in global affairs. Rome's collapse was precipitated by numerous internal factors, but it also faced strengthening external threats that capitalised on the internal chaos of the western empire. The small tribes which had fought the empire for years on the margins of their territory joined forces to form more powerful coalitions that the empire was unable to resist with its border armies. Even toward the very end, the well-financed and organised Roman military was formidable, but too often Rome found itself wasting resources it desperately needed to survive on costly internal divisions. After the fall of the western empire, the eastern empire, which had separated years earlier, fought mightily to recover the territories lost to the Germanic tribes in the west. But it was a foolish endeavour. Emperor Justinian's attempts to re-conquer the west proved too difficult and merely wasted treasure and manpower. The eastern empire would have been far better off consolidating its defences to prepare for what new threats would come later rather than throwing good resources after bad. And thus the Roman empire, both east and west, found itself an increasingly small voice in a region of the world which once called them master. As Barack Obama prepares to take office, some are predicting that America has reached the limits of its superpower status and is now facing a decline in our ability to shape world events. America, like Rome, seems to play by different rules from other nations in world affairs, a nod to the idea of "American exceptionalism" and Reagan's "Shining city on a hill".

By virtue of its economic and military power, as well as a political system extolled for its superiority to all other systems, America has been the leader of the free world for the last 60 years. But from China's rapidly rising status as a global player, to Russia's show of force in Georgia, to rising tensions in South Asia and the Middle East, America is facing a wide array of increasingly troubling threats, while struggling internally to recover from an economic collapse not seen since the Great Depression. American supremacy in a post-cold war environment seems outmatched by a progressively more unstable world.

Like Rome, America has spread itself too thin and is unable to respond to new threats as they emerge with either a convincing show of military force or a skilled use of soft power to leverage its credibility in the world. While the dangers we face were once diverse and scattered, the Iraq war pushed many of our enemies to see us as a common threat where religious differences would have otherwise made cooperation impossible. Moreover, in collapsing the Ba'athist regime of Saddam Hussein, America has paved the way for an even less palatable Iranian dominance in the region. While the comparison to ancient Rome is imperfect, there are nonetheless parallels worth considering. America today faces the same dilemma of the eastern Roman empire: should it attempt to regain its lost global supremacy or fortify and adapt to the new world? Will we follow Virgil's famous line from the Aeneid, "Rome, 't is thine alone, with awful sway, To rule mankind, and make the world obey," or preserve our strength and create a framework for global cooperation in which America acts as a mediator and responsible actor rather than instigator.

To be sure, America still boasts a powerful military and massive nuclear arsenal, and even under the most dire economic predictions, it is still a key player in global commerce. But if Roman history is any lesson, America must humble itself to its new position and work as a global partner instead of seeking to once again control the world in the palm of its hands. Hopefully America possesses the self-awareness that Rome did not, and will work to advance an agenda driven less by Machievelli than by self-interested cooperation.