Whether invoked by a new-conservative in the George W Bush administration or denied by a liberal in Obama’s, America is an empire. But for decades the reach and influence of that empire were checked by the existence of other empires. The thirty years since the end of the Cold War and the defeat of the Soviet Union, was a unique moment in history. America became the sole empire in the world.

Now that moment is coming to an end, and geo-strategists are busy thinking about the multitude of scenarios of how the American empire will interact with the rising power, China, that is determined to and highly likely will be an empire.

Yet, what is happening inside America merits close attention, for it has major influence over how America will interact with China and in the rest of the world.

American politics are becoming much more polarised than at any point since the end of the Civil War and the period of reconstruction of the south that followed in the second half of the nineteenth century. This polarisation transcends the Republicans and Democrats descending into wars of words to discredit the other. Today’s polarisation has become socially entrenched, in terms of opposing (and not just different) views of what America means and what its social order ought to be.

This polarisation stems from different identities and ways of living, rather than from political positions or economic interests. This is important, because it means political contestation in America is no longer based on seeing the other as intellectually wrong, rather on seeing the other as belonging to a different moral (and spiritual) place. When societies arrive at this point, politics typically become paralysed.

The public space becomes increasingly empty. If one faction sees the other as intellectually, morally, and spiritually corrupt (or at best utterly mistaken), it will not only not discuss with it. It will try to cut its links to anything that it has to do with it.

This is already happening in different parts of the US, not only geographically, but also culturally. The result is that the common social space – that the nation as a whole used to come to to debate, discuss, and find compromises – initially loses its centrality, then gradually disappears. The diminishing importance of American newspapers, traditional centres of excellence (for example top universities), national tv networks, and the cultural unifying threads (think the notion of the great American novel that captures the national moods and sentiments) are cases in point. Some might say the extreme bipartisanship at Congress is the most glaring example.

As the political contestation becomes that of opposites, representing not only different viewpoints, but also convictions, ways of life, and identities, the other could well become more than ‘different’ or even ‘wrong’; it could become “evil”.

American political rhetoric has often combined the sacred with the secular. More than in any Western country, God has always had a central presence in America’s politics. (Yet, it is important to emphasise that the most influential Founding Fathers, the initial architects of the American project at its birth-moment, saw God in grander hues than those gleaned from anthropomorphic understandings). And as articles of faiths, and views stemming from what is “good” and what is “evil” take centre stage in any highly polarised polity, demonising the other quickly follows.

As a result, the centre is diluted, and power is fragmented. The traditional nodes of power in America get marginalised in favour of powers that were traditionally on the margins. We are already seeing this as far-right (and to some extent, far left) groups that were always on the fringes are now at the centre of the two American political parties.

Why should the rest of the world care?

Because what happens in America has always affected how it deals with the world. And now at this moment when China’s rise is bringing American hegemony over the world to an end, the effect of the inside on the outside is particularly important.

The situation is historically unique. Never before in modern history (at least in the past three centuries) did an empire rule supreme in the world. There are no precedents here for how America will behave at this moment of global transition.

America’s internal dynamics accentuate the uncertainty. The acute polarisation in what constitutes American values, frame of reference, and way of life would translate into acute differences on what its national interests are, its role in the world is, and what it is willing to do to defend these interests.

Polarisation is highly unlikely to lead America to over-aggressive or over-acquiescent positions with regard to China. But the diverging views that result from polarisation could well lead to confusion and chaos, or at least to a weakened decision-making process. Previous foreign policy mistakes have cost America dear, but serious mistakes in delicate geo-political situations (such as dealing with China at this moment in history) are of a different order of magnitude. They will have serious consequences for the whole world. This is because the interaction between America and China in the coming decade will affect international trade, the functioning of the most important international institutions, the development of revolutionary technologies, the global economy, and of course politics in different parts of the world.

Dousing the demon of acute polarisation in American society will benefit many parts of the world, not just America.

As for those who have always looked with admiration at the intellectual rigour of the original American project, they look at today’s American politics with surprise and wistfulness.