NEW DELHI – After a run of nearly one thousand years, quipped the French philosopher and writer Voltaire, the fading Holy Roman Empire was neither holy nor Roman nor an empire. Today, some two and a half centuries later, the problem, to paraphrase Voltaire, is that the fading liberal world order is neither liberal nor worldwide nor orderly.

The United States, working closely with the United Kingdom and others, established the liberal world order in the wake of World War II. The goal was to ensure that the conditions that had led to two world wars in 30 years would never again arise.

To that end, the democratic countries set out to create an international system that was liberal in the sense that it was to be based on the rule of law and respect for countries’ sovereignty and territorial integrity. Human rights were to be protected. All this was to be applied to the entire planet; at the same time, participation was open to all and voluntary. Institutions were built to promote peace (the United Nations), economic development (the World Bank) and trade and investment (the International Monetary Fund and what years later became the World Trade Organization).

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All this and more was backed by the economic and military might of the US, a network of alliances across Europe and Asia, and nuclear weapons, which served to deter aggression. The liberal world order was thus based not just on ideals embraced by democracies, but also on hard power. None of this was lost on the decidedly illiberal Soviet Union, which had a fundamentally different notion of what constituted order in Europe and around the world.

The liberal world order appeared to be more robust than ever with the end of the Cold War and the collapse of the Soviet Union. But today, a quarter-century later, its future is in doubt. Indeed, its three components – liberalism, universality, and the preservation of order itself – are being challenged as never before in its 70-year history.

Liberalism is in retreat. Democracies are feeling the effects of growing populism. Parties of the political extremes have gained ground in Europe. The vote in the United Kingdom in favor of leaving the EU attested to the loss of elite influence. Even the US is experiencing unprecedented attacks from its own president on the country’s media, courts, and law-enforcement institutions. Authoritarian systems, including China, Russia, and Turkey, have become even more top-heavy. Countries such as Hungary and Poland seem uninterested in the fate of their young democracies.

It is increasingly difficult to speak of the world as if it were whole. We are seeing the emergence of regional orders – or, most pronounced in the Middle East, disorders – each with its own characteristics. Attempts to build global frameworks are failing. Protectionism is on the rise; the latest round of global trade talks never came to fruition. There are few rules governing the use of cyberspace.

At the same time, great power rivalry is returning. Russia violated the most basic norm of international relations when it used armed force to change borders in Europe, and it violated US sovereignty through its efforts to influence the 2016 election. North Korea has flouted the strong international consensus against the proliferation of nuclear weapons. The world has stood by as humanitarian nightmares play out in Syria and Yemen, doing little at the UN or elsewhere in response to the Syrian government’s use of chemical weapons. Venezuela is a failing state. One in every hundred people in the world today is either a refugee or internally displaced.

There are several reasons why all this is happening, and why now. The rise of populism is in part a response to stagnating incomes and job loss, owing mostly to new technologies but widely attributed to imports and immigrants. Nationalism is a tool increasingly used by leaders to bolster their authority, especially amid difficult economic and political conditions. And global institutions have failed to adapt to new power balances and technologies.

But the weakening of the liberal world order is due, more than anything else, to the changed attitude of the US. Under President Donald Trump, the US decided against joining the Trans-Pacific Partnership and to withdraw from the Paris climate agreement. It has threatened to leave the North American Free Trade Agreement and the Iran nuclear deal. It has unilaterally introduced steel and aluminum tariffs, relying on a justification (national security) that others could use, in the process placing the world at risk of a trade war. It has raised questions about its commitment to NATO and other alliance relationships. And it rarely speaks about democracy or human rights. “America First” and the liberal world order seem incompatible.

My point is not to single out the US for criticism. Today’s other major powers, including the EU, Russia, China, India, and Japan, could be criticized for what they are doing, not doing, or both. But the US is not just another country. It was the principal architect of the liberal world order and its principal backer. It was also a principal beneficiary.

America’s decision to abandon the role it has played for more than seven decades thus marks a turning point. The liberal world order cannot survive on its own, because others lack either the interest or the means to sustain it. The result will be a world that is less free, less prosperous, and less peaceful, for Americans and others alike.