World leaders are visiting the UN the week of 18 September for the annual high-level meeting of the General Assembly at a testing time for the organization. Major-power divisions are shrinking the space for multilateral cooperation, and the organization’s role in managing international peace and security crises is increasingly uncertain.

While UN peace operations and humanitarian assistance are helping contain conflict and suffering in many countries, the organization’s political influence is decreasing. Hamstrung by political divisions and resource gaps, the UN’s leadership and member states must develop new strategies for mobilizing the organization’s strengths to meet peace and security challenges.

The UN must be pragmatic, endorsing tools like blue helmet peacekeeping in some crises and ad hoc, regionally led responses in others. The UN will sometimes be limited to delivering humanitarian aid and seeking modest political traction. UN platforms can also help address threats like climate change and artificial intelligence.

The geopolitical constraints on the UN are not new, but their effects on the organization are intensifying. There were deep rifts among Russia, China and the Western powers in the Security Council before Moscow’s all-out invasion of Ukraine. Yet while debates over Ukraine dominated UN business from February 2022 onward, the Council was initially able to keep working on other issues more or less constructively. It was even able to innovate in thorny cases, passing its first full resolution on Myanmar and establishing a new system of humanitarian exemptions to UN sanctions regimes in late 2022.

The UN Secretary-General António Guterres also played a notable part in mitigating the global fallout from the Russian-Ukrainian war by helping broker the Black Sea Grain Initiative. But as the war has ground on through 2023, the room for residual major-power cooperation through the UN has started to narrow, and diplomats have found it harder to make compromises on difficult issues than in 2022. Russia quit the grain deal in July. It has acted as a spoiler in the Security Council with growing frequency.

As the geopolitical picture darkens, the Council has managed only lackluster responses to many of the crises of the last year. It has done little more than make statements of concern on cases ranging from the collapse of Sudan in April to the coup in Niger in July. Regional actors have increasingly aimed to take the lead in resolving these situations, albeit with little success, leaving the UN on the sidelines. The government in Mali has underlined the Council’s weakness – and the vulnerabilities of UN blue helmet missions – by demanding the withdrawal of peacekeepers from Malian territory, despite the attendant risk of new violence.

Outside the Council, many UN members have pushed the organization to focus on global economic problems rather than peace and security issues. The General Assembly frequently debated Ukraine in 2022. In contrast, the countries of the so-called Global South have insisted that the Assembly should concentrate on development in the run-up to the high-level meetings, with a focus on making the World Bank and International Monetary Fund (IMF) more responsive to poor and middle-income countries’ needs. Although the U.S. and its allies have resisted parts of this agenda, they have acknowledged the need to update the international financial system, not least to counter Chinese and Russian influence among developing states.

Despite enduring a difficult year, and facing the probability of another hard year ahead, the UN still has significant operational and diplomatic roles to play in managing both traditional and emerging threats to international peace and security.

The world leaders who gather at Turtle Bay in September should look for common ground on international security issues, as well as economic ones, and take up the Secretary-General’s call to face the new generation of global threats together – rather than accept the decline of multilateralism as inevitable.

If the Security Council has often faltered in 2023, the General Assembly has also stepped back from playing a significant role in peace and security matters. During the initial months of Russia’s all-out war in Ukraine, the Assembly was unusually prominent in guiding the UN response, repeatedly passing resolutions condemning Russia by large margins. Diplomats wondered if this activity presaged a broader increase in the Assembly’s engagement in crisis management, noting that the body – where every member has one seat and none has a veto – has stepped up in other periods of the UN’s history when the Council has floundered.