The contest to succeed António Guterres as Secretary-General of the UN has begun. Whoever takes the reins in January 2027 will need to steer the UN through geopolitical turbulence and financial crisis at a moment when even diplomats and UN officials based in New York openly question the organisation’s relevance in world affairs. 

The selection process, which commenced in November 2025, consists of three stages. Member states must first nominate candidates to the UN General Assembly and Security Council. At the time of publication, there are four candidates officially in the race. Rafael Grossi, director general of the International Atomic Energy Agency, was nominated by his native Argentina and Rebecca Grynspan, secretary general of UN Trade and Development, by her home country of Costa Rica. Former Chilean President Michelle Bachelet and former Senegalese President Macky Sall were nominated not by the current leadership in their countries of origin but rather by continental neighbours: Brazil, Chile and Mexico jointly nominated Bachelet, though Santiago withdrew its support after a change in government in March; Burundi nominated Sall. Additional contenders may emerge as the year goes on, entering the race at a late stage as a way to avoid prolonged scrutiny or to position themselves as compromise candidates. In July, the Security Council will begin holding informal polls, continuing until one candidate receives at least nine votes from the fifteen-member body with no objection from any of the five permanent members. Once a candidate crosses this threshold, the Security Council will send the recommendation to the General Assembly (which has never rejected the Council’s choice) for formal appointment.

While diplomats say they are uncertain about how the selection process will play out, most agree that they would like to see it produce a Secretary-General who is focused on crisis diplomacy and conflict resolution. At times during Guterres’ term, both he and member states have de-emphasised peace and security when discussing the UN’s future, on the assumption that in a period of big-power competition the organisation is better positioned to help broker agreements on issues like climate change, artificial intelligence and pandemic responses. But at a moment of international instability, questions about the UN’s role in war and peace will invariably take centre stage as the organisation chooses a new leader.

Other pressures will shape member states’ calculations. One is the decades-long push – joined in the last two years by countries including Brazil, South Africa, Spain and Uruguay – for the organisation to appoint its first woman Secretary-General. Another is Latin American states’ insistence that the next UN chief come from their part of the world, in line with a non-binding and imperfectly observed convention that the post should rotate among regions (the one previous Secretary-General from Latin America, Javier Pérez de Cuellar, served from 1982 to 1991). 

How these factors will play out in the campaign is uncertain. Some diplomats warn that woman contenders could be unfairly stereotyped as less well-suited to handle peace and security than male rivals. There is also a sense that the U.S. will see its stance on what it refers to as combating “gender ideology” and “discriminatory equity ideology” as clashing with efforts to promote the selection of a woman Secretary-General. The Trump administration’s preferences will, of course, influence how other member states and the candidates position themselves ahead of the selection gauntlet. But these issues aside, a demonstrated capacity to do the job will be key. Every candidate should come equipped with ideas for bolstering UN’s credibility on international peace and security as central to his or her strategy for helping the UN withstand this moment of intense geopolitical pressure.

The next Secretary-General will take office at a time when the organisation’s influence is waning. This decline is in no small part due to a Security Council that has buckled under the weight of major-power dissension and the erosion of respect for international law. The U.S. and Russia have become more brazen in their willingness to act in seeming defiance of the UN Charter, most recently with Russia’s all-out invasion of Ukraine, the U.S. decapitation operation in Venezuela and the U.S.-Israeli attacks on Iran. Combined with shifting and unstable dynamics among the permanent members (especially between the U.S. and its big-power counterparts), diplomats have found less and less space to work through the Security Council to end wars, rendering the body unable to respond decisively to major conflicts.

But the Secretary-General cannot blame all the UN’s woes on the Council. Sensitive to the risk of failure, Guterres has brought a culture of caution to the entire UN peace and security architecture despite promising a “surge in diplomacy for peace” when he assumed office. Formerly the head of the UN refugee organisation, Guterres has frequently expended his political capital on supporting humanitarian operations instead of peacemaking efforts. He has achieved one especially prominent success in the former category, winning praise for his role in forging the Black Sea Grain Initiative involving Russia and Ukraine in 2022. He is proposing a similar mechanism to help resume commercial fertiliser trade through the Strait of Hormuz. 

These initiatives to mitigate the consequences of conflicts stand in contrast to Guterres’s reluctance to directly engage in peacemaking efforts. He has largely stepped back from high-profile peace efforts after his direct involvement in Cyprus and Libya talks during his first term produced limited results. He has more readily dispatched his humanitarian advisers and personal envoys. Moreover, while Guterres has championed regionally led peacemaking and security operations, especially through the African Union (AU), he has struggled to carve out clear lanes for the UN to offer complementary political support.

Though multilateral peacemaking institutions are on the decline, the UN’s trajectory is not preordained. The next Secretary-General will have an opportunity to lay out a new approach, ideally one that places more emphasis on the UN head’s own role in mediation and sharpens the organisation’s impact on conflict prevention and crisis management. Of course, it is easier said than done. But candidates can begin laying down markers for how those goals might be reached. 

Guterres’s successor will have the task of restoring the UN’s credibility as a peacemaking institution. Part of doing so will depend on whether the new leader can rebuild trust and improve lines of communication between the UN Secretariat and major powers (including but not limited to the Council’s permanent members). Burnishing the Secretariat’s diplomatic bona fides should be near the top of the list. 

While major-power contestation is particularly severe at present, past Secretaries-General embraced their responsibility to act as honest brokers among major powers in wartime. UN officials and diplomats have lately been reading and recommending a new biography of U Thant, the Secretary-General who steered the UN through the turbulent 1960s and was directly involved in diplomacy over the Cuban missile crisis and the Vietnam war. How to play a corresponding role in the current panorama is the first big dilemma that the next Secretary-General will need to confront.

For starters, the next Secretary-General should encourage the veto-wielding powers to preserve, and in some cases expand, the Security Council as a space for diplomacy. While there is no precise formula for encouraging more meaningful diplomatic exchanges among the world’s most powerful countries in New York, the UN’s next “chief diplomat”, as the Secretary-General is often called, must be more proactive in sensing potential openings and doing more to make use of them. Close personal relations with the permanent members can help the Secretary-General send quiet messages about the risks of miscalculation or unintended escalation, as well as probe for opportunities to advance diplomacy. Though a personal touch is particularly helpful in dealing with first-order conflicts, the next Secretary-General may also need to use one more frequently on files like Afghanistan, Colombia or South Sudan, places where the Council’s historical unity is coming under greater geopolitical strain. 

Maintaining the UN’s relations with the capitals of three of the permanent members – China, Russia and the U.S. – will be central to the new Secretary-General’s success. Beijing’s relationship with the UN has grown in significance as China has emerged as a swing vote on sensitive Council files, in addition to becoming the organisation’s second largest funder. At the same time, the UN’s relations with Moscow and Washington are at a low point. Moscow has largely given Guterres the cold shoulder since he rightly condemned Russia’s all-out invasion of Ukraine in February 2022. U.S. President Donald Trump has paid little heed to the UN: despite issuing half-hearted appeals for the organisation’s help to support his peacemaking pursuits, he has spoken with Guterres just once during his second term and has pitched his Board of Peace as a potential competing power (in spite of its narrow Security Council mandate to oversee the ceasefire in Gaza). The next Secretary-General will have some backing from the veto powers when the new term begins; diplomatic artistry will be needed to take advantage of this opening to push for bold peacemaking efforts while also recasting the UN’s relations with the three big powers in particular.

But rebuilding the organisation’s credibility as an international peacemaker will depend on more than the veto powers, helpful as they might be. Guterres’s successor will need to cultivate support from a broad swathe of countries to back the UN and provide the Secretary-General’s office with a wider range of diplomatic levers. Though the cohesion and influence of the Council’s ten elected members fluctuates based on the group’s composition, the UN’s next leader should support those states that are willing to conduct back-channel negotiations among the permanent members. For example, shortly after Russian troops poured into Ukraine in early 2022, Norway facilitated Council negotiations over renewing the UN political office’s mandate in Afghanistan for the first time after the Taliban takeover.

Outside the Council, Guterres’s successor will confront UN member states whose commitment to the organisation varies wildly. European and other wealthy countries like Canada and Japan will continue to throw their political support behind the UN, but they are unlikely to fill the budget gaps left behind by the U.S. retreat. Non-Western middle powers, including Brazil, Egypt, the Gulf Arab states, India, Kenya, Mexico, Pakistan, South Africa and Türkiye, among others, wield considerable diplomatic and economic heft in their regions, but they do not always coordinate closely with the UN, due in part to the Council’s diminished legitimacy and the limited prospects for its reform. The next Secretary-General should encourage cross-regional coalitions that can buttress UN peacemaking efforts, particularly when a veto power is either directly involved in the conflict or blocking diplomatic action by the Security Council. For example, on the margins of the 2025 UN General Assembly meetings eight Arab and Islamic countries importuned the U.S. to back ceasefire negotiations in Gaza. 

Beyond the UN, the next Secretary-General will need to weigh whether and how to bring smaller minilateral bodies into the fold of diplomatic efforts. To be sure, the UN has established partnerships with regional organisations like the AU and European Union, which have explicit peace and security mandates. But other groups are gaining influence. Some, like the expanded BRICS (which encompasses countries ranging from Brazil to the United Arab Emirates) and the Shanghai Cooperation Organisation (which includes China, Russia and India), are amassing economic clout at a moment when regional security and economic interests are closely intertwined. While many at the UN see the value of working in concert with other multilateral partners, the next Secretary-General will need to answer thornier questions about how to balance the UN’s role in a more multipolar world with organisations that are heavily shaped by major powers at the centre – understanding where there is space for constructive collaboration.

Candidates will also need to demonstrate that they can repair the Secretariat’s credibility on prevention and peacemaking. This endeavour will entail improving the quality and ambition of ideas that the organisation can put on the table, including when it does not have an explicit operational mandate from the Security Council. 

The Black Sea grain deal is often seen as a hallmark of the UN’s ability to address what Guterres has described as “interlocking threats”. It drew upon several types of technical expertise within the UN (including on peace and security, humanitarian relief and trade), leveraging the involvement of the Secretary-General and his leadership team, and addressed a tangible concern for many countries while avoiding anchoring the organisation to a long-term political process. But the creativity behind this initiative is more the exception than the rule. 

Security Council diplomats and UN officials alike acknowledge that the quality of ideas emerging from the UN system often falls short of their expectations. There are several factors at play, starting with the organisation’s leadership. Some Council diplomats felt that the Secretary-General’s reticence left them with less space to pursue creative solutions to peace and security challenges. In 2024, Guterres declined to consider an expanded operational presence for the UN in Sudan, including with the AU, despite an explicit Council request that the organisation propose ways to protect Sudanese civilians. A few months later, he instructed UN officials not to consider a new peacekeeping operation for Haiti as part of the “full range of options” that the Council requested of the Secretariat; the UN instead presented a single option for a logistics office to backstop the now defunct Kenyan-led police force. Throughout the war in Ukraine to date, Guterres has prevented UN officials from conducting scenario planning for a possible UN ceasefire monitoring mission in the absence of explicit requests from either Kyiv or Moscow. While geopolitical turmoil has frequently given the UN little latitude, UN watchers argue that the Secretary-General went too far in internalising these constraints and unhelpfully limited debate among member states about what the UN might achieve.

The selection of a new Secretary-General provides an opportunity to reset that culture. Guterres’s successor will need a higher tolerance for at least entertaining calculated and coordinated diplomatic risks to back peace processes while defending the norms of the UN Charter. This tolerance is all the more pressing at a moment when the risk of failure is intrinsically high and the UN risks reputational harm and blowback from member states both for what it does and what it does not do. 

In particular, Guterres’s successor should lean into the Secretary-General’s good offices mandate to spearhead solo diplomatic initiatives without explicit instructions from the Security Council. Guterres accomplished little in this regard. He did not factor prominently in diplomacy to halt the fighting in Ukraine or Gaza, two of the major wars that have dominated his second term in office. To some extent he was sidelined by his own principled and vocal defence of the UN Charter and international law, which minimised his space to be a credible interlocutor with Moscow and Washington. He also found that he had less room for manoeuvre than some past UN heads, who were able to dive into mediation of second- and third-order crises, like those in Nicaragua or Myanmar, with some success; by contrast, Guterres’s above-referenced efforts in Cyprus and Libya failed to gain significant traction. But even though Guterres struggled to use his position for effective personal diplomacy, the potential is still there. In seeking to unlock it, his successor will need to find a diplomatic register that is both morally forthright and yet not so confrontational so as to jeopardise access to decision-makers for the major powers.

But the next Secretary-General cannot single-handedly change the organisation’s standing on peacemaking. He or she will need the support of a diverse, credible cabinet that acts as a sounding board and mobilises ideas from throughout the UN bureaucracy. Key UN appointments – eg, the heads of Secretariat departments and field missions – are frequently heralded by intense member state lobbying, including by the five permanent members, which exert informal monopolies over the Secretariat’s core departments (like those of France over the Department of Peace Operations and the U.S. over the Department of Political and Peacebuilding Affairs). Guterres’s successor may not have the leverage to break informal traditions that trace back decades. But he or she should urge states to put forward highly qualified officials for these roles and, if necessary, turn down individuals who are neither willing nor prepared to offer a critical, impartial perspective.

Internal rewiring may also be required to support a cultural reset. Some departments, including Peace Operations, Political and Peacebuilding Affairs, and the UN Development Programme, tend to control internal debates about particular country or thematic files. Often driven by bureaucratic or budgetary incentives, this practice limits international officials’ abilities to integrate expertise from other parts of the organisation. Guterres attempted to mitigate this longstanding problem with institutional reforms in 2019, but he only achieved limited success. Some UN officials suggest that the Secretary-General and senior management need to set clearer expectations for different parts of the organisation to align their efforts. Others argue that the Secretariat should invest in a dedicated planning cell that supports the peace and security pillar, which could both improve the quality of proposals emerging from the Secretariat and reduce the likelihood that policy options put on the table are coloured by turf battles.

If the next Secretary-General is going to bolster the organisation’s efforts on peace and security, it will have to happen under severe geopolitical pressure and with reduced resources. As Crisis Group has previously reported, most member states hold a residual interest in UN peace operations as an enduring contribution the organisation can make to international security. But the UN’s flagship tools have come under strain. 

Amid dwindling interest in the UN as a conflict management actor, the Security Council has struggled to agree on the political roles its peace operations should fill: it has mandated no new peacekeeping operation since 2014 and stood up only a handful of civilian missions in that period. Those operations that do not enjoy unanimous backing from the permanent members (like missions previously deployed in Mali and Sudan) have been vulnerable to the host government’s political whims, regardless of whether the conditions on the ground warrant changes to the UN’s presence. The Trump administration has evinced scepticism about longstanding UN missions, while forcing the UN to shave nearly 20 per cent off the peacekeeping budget and impose strict cash conservation measures that affect missions’ daily operations. Additional cuts appear to be on the cards for 2027. 

Questions about the trajectory of the UN’s flagship tool have dogged Guterres for much of his term. He will share his final note on the subject – a review on “all forms of UN peace operations” – by July as part of an exercise mandated in the 2024 Pact for the Future. Officials suggest that the Secretary-General will push member states for stronger political backing of UN operations while proposing modest reforms in areas like mandating practices and consultations with host governments. Few expect Guterres to spend his final months in office pushing for the implementation of these recommendations, leaving room for his successor to shape what comes next.

The next Secretary-General will need to make the case for the positive roles that UN missions can take on in fractured political landscapes. The UN – through both multidimensional peacekeeping operations and civilian-led political missions – has decades of experience with tasks that deployments from other multinational organisations are unwilling or unable to perform. Often, the UN is the last line of defence in protecting civilians or the only multilateral institution with the legitimacy to help see through peace deals as international attention fades. The difficulties inherent in finding personnel for and funding alternatives to UN-led missions – like the Kenyan-led police mission in Haiti or the International Stabilisation Force mandated as part of the Gaza ceasefire plan – demonstrate that the UN’s operational and financial infrastructure cannot be easily replicated, even if other multilateral bodies take the lead. For all the flaws of UN peace operations, they would be sorely missed in international conflict management should their number dwindle further.

Whoever leads the organisation next will have to help the Security Council adapt mission mandates to new political realities. Most UN officials and diplomats agree that future missions will need to be both smaller and oriented around a narrower, more streamlined set of tasks, at least relative to the past two decades of large multidimensional missions with Christmas tree mandates, ranging from the stabilisation mission in the Democratic Republic of Congo to the peacekeeping operation in South Sudan. While supporting peace processes and protecting civilians should continue to feature prominently in UN mandates, other functions will inevitably come under heightened scrutiny. The U.S., China and Russia may attempt to further constrain UN missions’ work on both the women, peace and security and climate security fronts. Council members that support these normative agendas will be at the forefront of pushing back against any revisionist pushes. The next Secretary-General should keep providing clear evidence of how each mission’s work in these areas contributes directly to peace processes and civilian protection, to support arguments in favour of maintaining relevant tasks.

Separately, discussions about UN peacekeeping’s funding model may come into the spotlight early in the next Secretary-General’s term. Washington’s à la carte approach to UN peacekeeping – ie, its funding of only a handful of operations instead of its full share of the total budget – has led some diplomats to question the viability of a financial model that depends so heavily on two countries, the U.S. (approximately 26 per cent) and China (approximately 24 per cent), to supply nearly half the money needed each year. The General Assembly will undertake triennial reviews of UN peacekeeping’s formula allocating costs (the scales of assessment) during the next Secretary-General’s first term. President Trump may attempt to reduce the U.S. contribution to UN finances, similar to how he assailed NATO allies for not paying what he perceived to be their fair share to that organisation.

Major revisions to these formulas are unlikely in the short term and would do little to alleviate the organisation’s cash shortages. Negotiations over the payment formula will be politically fraught, as any attempt by the U.S. or China to cut its contribution would inevitably place a larger financial burden on a handful of countries (Canada, France, Germany and Japan) that are already bending to Washington’s insistence on higher defence expenditures as well as other powers with large economies (Brazil, India, Indonesia and Saudi Arabia) that are dealing with other economic shocks. The next Secretary-General cannot unilaterally drive the politics or process of these negotiations. But he or she could map out a plan to maximise whatever resources member states may be willing to give. 

A larger related point is that UN member states will need to envision what kind of peace and security organisation they want to see over the coming years. Who they select to be the organisation’s next Secretary-General will speak volumes about that vision or the lack thereof. Hopefuls for the job may conclude that taking bland, inoffensive positions will help them survive the permanent members’ gauntlet. But the best contenders will be able to communicate to member states the value of investing more in both the UN’s crisis diplomacy and in its peacemaking mechanisms as a way of helping stabilise a turbulent world. They do not need to frame their pitches as challenging the veto powers or any other group of states; they can simply say they wish to put the UN Charter’s call to stem the “scourge of war” into practice. Candidates who pass this test will have demonstrated one of the skills that will be required to do the job. 

At a moment when major powers are willing to disregard the global order and states are losing faith in international institutions, the need for a Secretary-General prepared to defend a clear, proactive vision for the UN on peacemaking and crisis management could not be more urgent. The selection process should be the first step toward redrawing the profile of the UN’s “chief diplomat” amid severe geopolitical and financial pressures. If candidates and member states miss this opportunity, there may be little left of the UN to defend.