President Donald Trump signs executive orders, 20 January 2025. The Trump White House, Public domain, via Wikimedia Commons

In January, President Donald Trump signed a presidential memorandum pulling the US out of 66 international organisations and instruments, including 31 UN entities. His administration views the organisations as being ‘wasteful, ineffective, and harmful’ to America’s ‘sovereignty, freedoms, and general prosperity’, while commentators say the exit of the US is a blow to decades of international norm setting, with implications for the operations of bodies tackling some of the world’s most pressing challenges by promoting peacebuilding, human rights, the rule of law and climate action.

‘The Trump administration’s conception of international law and international relations is very different than past administrations,’ says Michael Showalter, an officer of the IBA Environment, Health and Safety Law Committee.

Some previous US administrations have argued that laws and norms shouldn’t be dictated by supranational entities and have exited international treaties they didn’t support. Notably, President George W Bush withdrew the US signature to the Rome Statute, which established the International Criminal Court. And President Trump had already pulled the US out of the World Health Organization, the UN Human Rights Council, UNESCO and the Paris Agreement.

But this latest move goes far beyond anything a US president has done before.

Among the organisations the US is leaving are bodies working to strengthen counterterrorism and uphold the rights of children, women and victims of conflict and sexual violence. The list also includes organisations working to promote the rule of law, such as the International Law Commission. This organisation comprises a rotating group of experts established by the UN General Assembly in 1947 to help develop and codify international law.

Most organisations will continue to operate without the US. But for many cash-strapped entities, the extent of what they’ll be able to do will depend on the willingness of the international community to fill the gap left by Washington’s retreat. ‘The US have sent a clear signal [as to] which issues they consider relevant for international cooperation – and which ones they do not,’ says Markus Beham, Co-Chair of the IBA Human Rights Law Committee.

At the same time, holding eulogies to international law and the UN as a whole is ‘surely premature if not overall ill-founded,’ says Beham, who is Chair of Public International and European Law at the European University Viadrina in Frankfurt. ‘After all, the US still continues to operate within its framework wherever they find the channels to operate efficiently for conducting their international affairs.’

One area where the Trump administration appears to have little intention of working with international partners is in respect of addressing the climate crisis. President Trump has previously called climate change ‘a hoax’ and has overseen a sweeping rollback of related federal policies, including the revocation in January of the 2009 ‘endangerment finding’, which held that a range of greenhouse gases are a threat to public health and the environment and therefore should be regulated by the US Environmental Protection Agency. The finding has thus been used as a foundation for federal efforts to tackle emissions, such as those produced by vehicles.

President Trump has said that repealing the finding will mean a decrease in costs for US car manufacturers. Environmental advocates have meanwhile warned that the repeal could disrupt the energy transition and climate investment over the long-term.

The January memorandum pulls the US out of around a dozen organisations advancing cooperation on addressing global warming, biodiversity loss and energy. This includes the UNFCCC, the international treaty that underpins cooperation on climate action. The Trump administration’s rationale is that membership ‘no longer [serves] American interests’ and ‘wastes’ US taxpayer money.

The move has sparked ‘a very interesting’ question about the legality of using a memorandum to pull the US out of the treaty since its ratification was approved by a two-third majority in the Senate, says Showalter, who’s a partner at ArentFox Schiff, based in Chicago and New York.

The US Constitution makes no reference to exiting international bodies and agreements and the Supreme Court hasn’t ruled on the issue. Some legal scholars argue that the President has no general unilateral power to do so. Others suggest that, in practice, the President’s ability to withdraw from treaties without the approval of Congress has been accepted. Other scholars meanwhile have looked at the question of whether a future administration would be able to rejoin the UNFCCC without the need to seek new consent from Congress.

‘The US was never the most reliable country in terms of climate governance,’ says Showalter. But at the sub-national level, states such as Michigan are taking ‘very aggressive action’ by suing fossil fuel companies on climate grounds, he says.

America’s long-term and structural retreat from the climate regime will also reverberate at the international level. ‘Withdrawal may force the world towards a fragmented landscape of bilateralism and climate clubs,’ says Rajat Jariwal, an officer of the IBA Environment, Health and Safety Law Committee. ‘The regime is not expected to collapse, but it will most definitely become less coherent […] and dilute the peer pressure dynamics that drive ambition.’