For decades after World War II, it was difficult to imagine the geopolitical West – and the rules-based international order more broadly – without the leadership of the United States. But since US President Donald Trump’s return to the White House, the survival of any semblance of US leadership now appears practically inconceivable – a shift that the ongoing session of the United Nations General Assembly will only reaffirm. America’s Western partners will need to adapt to the new reality by reducing their dependence on the US and improving coordination among themselves.

There is little doubt that Trump’s America cannot and should not be trusted. Trump displays open contempt for America’s allies, while praising strongmen like Russian President Vladimir Putin. He decries global climate action as an effort by “foreign capitals and global activists” to “handicap” the US economy and “gain wealth at [America’s] expense”. His administration’s war on vaccines promises to not only make Americans sicker but to allow diseases to fester and spread in many corners of the world. And he shows deep disdain for international rules and norms, not least those governing the global trading system.

Trump is merely the most obvious symptom of a problem that has been worsening for decades within the US. Between 1980 and 2022, America’s real GDP per capita doubled, yet its real median household income increased by less than a quarter. This was no accident. A series of Republican presidents – from Ronald Reagan through Trump – cut taxes for the wealthiest, claiming that the benefits would “trickle down” to the rest of the economy. Meanwhile, a combination of automation and offshoring eroded America’s manufacturing sector, destroying many workers’ economic security.

Assuming that Trump adheres to the US Constitution and leaves the White House in January 2029 – which no one should take for granted – his departure would not fix these problems. Even if the Democrats gain congressional majorities in next year’s mid-term elections, and their nominee wins the presidency in 2028, the populist forces that propelled Trump’s rise will continue to shape US politics.

Ill-conceived, ham-fisted policies, such as those intended to “contain” China, will continue to divert resources from measures – such as rebuilding the country’s decaying infrastructure – that would bolster America’s social resilience, growth potential, and competitiveness. And US global leadership will continue to decline.

Against this backdrop, the “rest of the West” must step up to preserve the foundations of global stability and prosperity. These countries certainly have what it takes to make a difference. It includes plenty of prosperous and influential “middle powers” – namely, the 27 members of the European Union, the United Kingdom, Japan, South Korea, Australia, New Zealand and Canada. In 2024, these countries had a combined population of almost 700 million – double that of the US – and their combined GDP, at US$29 trillion, was equivalent to that of the US.

By working together on trade and defence, these countries would strengthen their negotiating positions vis-à-vis the US. After all, if there is one thing Trump responds to, it is raw power. But their agenda should extend well beyond wresting better deals out of the Trump administration and include offsetting the impact of Trump’s capricious unilateralism and toxic Sinophobia on the rest of the world.

This will require cooperation in at least three key areas. First, as the US erects Trump’s Great Wall of Tariffs, this new bloc of willing multilateralists should supply global public goods, including strengthening the world trading system and international law more generally.

Second, these countries must rethink their approach to China. Yes, the country is a systemic rival to the West and, as long as it supports Russia’s war on Ukraine, it poses a geopolitical threat to Europe. But the West’s middle powers are not caught in some “Thucydides Trap” with China; conflict is far from inevitable. They should thus seek to reach practical agreements based on shared interests, particularly in areas like climate action and pandemic preparedness.

Finally, the West’s middle powers should stand up for democratic and humanitarian values, not least in Gaza, where Israel has shown nothing but contempt for them. Whereas Trump unequivocally backs Israel’s military adventurism and systematic killing of civilians, the “rest of the West” should push back, which France, Spain, the UK, Canada, Australia and others are starting to do by recognizing the State of Palestine.

Working together – not within the confines of a formal arrangement but rather based on a shared purpose and strategic vision – Western countries can solidify their positions in a fast-changing and increasingly multipolar global order. The objective should not be to impose their will on others, as the US has too often sought to do. Rather, they should leverage cooperation, including with groupings like Asean ( the Association of Southeast Asian Nations ), to prevent the world from spiralling into conflict, economic fragmentation and environmental disaster.

Chin-Huat Wong is a professor of political science at the Jeffrey Sachs Center on Sustainable Development at Sunway University in Malaysia; and Wing Thye Woo is a professor emeritus of economics at the University of California, Davis, a university chair professor at the China Economic Research Institute at Liaoning University, a visiting professor at the University of Malaya and a research professor at Sunway University.

Copyright: Project Syndicate