At a time when conflicts spill across borders, Am-Dafock – a town built on marshy ground in the far north of Central African Republic – offers a powerful example of why UN peacekeeping matters, even if such successes rarely make international news.

In response to the growing impact of the war in neighbouring Sudan in 2024, the UN peacekeeping mission – known as Minusca – established a temporary base at the border town near Birao to protect displaced and refugee communities and create stability for the delivery of life-saving aid.

Last year, intercommunal tensions in the area forced from their homes more than 11,000 people, who sought refuge by camping near the UN base.

In response, Minusca peacekeepers facilitated a dialogue that led to the signing of a local peace agreement, between CAR and the Sudanese communities. As a result, nearly all those displaced families returned to their homes.

This is just one example of what investing in peace looks like.

Every day, more than 50,000 civilians, military and police peacekeepers serve under the UN flag in some of the world’s most complex and dangerous environments.

At a time when conflicts are multiplying, political divisions are deepening and populations are increasingly under threat, UN peacekeeping remains one of the most effective and cost-efficient tools for the international community.

On the International Day of UN Peacekeepers, we honour these women and men for their service, working under extremely difficult conditions to protect civilians and help prevent wider instability.

This week, we will honour 59 peacekeepers who lost their lives in service last year – a solemn reminder of the risks faced in places such as Lebanon, the Democratic Republic of the Congo (DRC), and Abyei between Sudan and South Sudan. We also remember more than 4,500 peacekeepers lost since 1948, when the first UN peacekeeping mission was deployed to the Middle East.

For almost eight decades, UN peacekeeping has been repeatedly tested. Today, the challenges posed by an increasingly divided world, by disinformation and by rapidly evolving technologies are compounded by serious financial constraints, which put growing pressure on our operations.

Delayed and incomplete contributions have forced missions to reduce their footprint across all 11 peacekeeping operations, with nine missions having to send a substantial number of troops home. Contracts have been cut and patrols, training activities and operational support have been reduced.

This has directly affected the ability of peacekeepers to maintain presence and sustain activities that communities rely upon. In the DRC, reductions in police personnel has contributed to a decline of about 30% in patrols, limiting access to remote and high-risk areas.

In South Sudan, the closure of field offices in Torit and Aweil has constrained efforts at political engagement and diplomacy, and reduced the mission’s ability to sustain protection of communities.

In Western Sahara, a drop in operational capacities has reduced the mission’s ability to observe multiple areas simultaneously, increasing the risk that violations may go undetected. In CAR there are fewer flights, limiting human rights monitoring and verification in remote areas.

These are the very real limits to what can be achieved when resources do not match the UN security council-set mandates for peacekeeping operations, even if they work hard to implement efficiencies and improve their performance. Yet despite these significant challenges, peacekeepers continue to make a tangible difference in the lives of millions.

One of the most overlooked aspects of peacekeeping is monitoring ceasefires. In places such as Cyprus and the Golan Heights in Syria, peacekeepers prevent local tensions from escalating and create the space necessary for diplomacy and political dialogue.

Peacekeeping is not an end in itself. Its purpose is political: to reduce violence, support political processes and help societies move from conflict towards durable peace.

When peace succeeds, it is because political agreements take hold and communities get the chance to rebuild. Peacekeepers help create the conditions for that process. In South Sudan, they support mobile courts that bring justice to communities where formal judicial systems are absent, helping break cycles of violence and impunity. In Abyei, teams work with communities to identify tensions early and prevent disputes from escalating. In the DRC and many other locations around the world, UN mine teams have helped to clear explosive hazards threatening civilians and peacekeepers.

Peacekeeping also keeps humanitarian lifelines open. In Bentiu, a town in South Sudan, peacekeepers maintain dykes protecting more than 300,000 people from catastrophic flooding and sustain critical infrastructure that connects vulnerable communities to humanitarian assistance and essential services.

These efforts require political will, sustained partnerships – including with regional, national and local actors – and predictable support from the international community.

Peacekeeping works because countries from around the world contribute personnel, expertise, resources and political backing.

Investing in peace is both a moral imperative and a strategic necessity. The cost of prevention and stabilisation is always far lower than the cost of conflict, displacement and instability. When peacekeeping missions are forced to scale back operations, the impact is felt immediately by the communities they serve.

The women and men serving under the UN flag cannot build peace alone. But their work continues to demonstrate that even in the world’s most difficult environments, it is still possible when the international community chooses to act together to support it.

For millions of people living through conflict, peacekeeping can mean the difference between fear and safety, isolation and assistance, despair and hope. Peace does not happen by accident. We must choose to invest in it.

• Jean-Pierre Lacroix is the United Nations under-secretary general for peace operations