The UN Security Council

Introduction

The UN Security Council (UNSC), the organization’s principal crisis-management body, is empowered to impose binding obligations on all 193 UN member states to maintain international peace and security. The Security Council—comprised of five permanent and ten elected members—meet regularly to assess threats to international security, including civil wars, natural disasters, arms proliferation, and terrorism.

Structurally, the Security Council has remained largely unchanged since its founding in 1946, stirring debate among members about the need for reforms. In recent years, members’ competing interests have often stymied the Security Council’s ability to respond to major conflicts and crises, including Syria’s civil war, the COVID-19 pandemic, Russia’s annexation of Crimea and 2022 invasion of Ukraine, and Israel’s war in the Gaza Strip.

What is the Security Council’s structure?

The Security Council has five permanent members—China, France, Russia, the United Kingdom (UK), and the United States—collectively known as the P5. Any one of them can veto a resolution. The Security Council’s ten elected members, who serve two-year, nonconsecutive terms, are not afforded veto power. The P5’s privileged status has its roots in the United Nations’ founding in the aftermath of World War II. The United States and the Union of Soviet Socialist Republics (USSR) were the outright victors of the war, and, along with the UK, shaped the postwar political order. 

As their plans for what would become the United Nations took shape, U.S. President Franklin D. Roosevelt insisted on the inclusion of the Republic of China (Taiwan), envisioning international security presided over by “four global policemen.” Meanwhile, British Prime Minister Winston Churchill, recognizing in France a European buffer against potential German or Soviet aggression, championed its restoration to great-power status.

The members of the P5 have exercised the veto power to varying degrees. Counting the years when the Soviet Union held its seat, Russia has been the most frequent user of the veto, blocking 159 resolutions since the Security Council’s founding, as of August 2025. The United States has used the veto ninety-three times, often to protect Israel from Security Council decisions. It last vetoed a resolution on June 4, 2025, which called for a ceasefire and for the lifting of restrictions on humanitarian aid entering Gaza. 

China has used the veto more frequently in recent years, too, though it has historically been more sparing than the United States or Russia. Beijing has blocked twenty-one resolutions, and Moscow has joined in on more than three-quarters of the resolutions that China has vetoed. In contrast, neither France nor the United Kingdom has exercised its veto power since 1989, and each has advocated for other P5 members to use it less.

The Security Council’s presidency rotates o­­­­n a monthly basis, ensuring some agenda-setting influence for its ten nonpermanent members, which are elected by a two-thirds vote of the UN General Assembly. The main criterion for eligibility is contribution “to the maintenance of international peace and security,” often defined by financial or troop contributions to peacekeeping operations or leadership on matters of regional security likely to appear before the Security Council.

A secondary consideration, “equitable geographical distribution,” gave rise to the regional groups used since 1965 in elections: The African Group has three seats; the Asia-Pacific Group, two; the Eastern European Group, one; the Latin American and Caribbean Group, two; and the Western European and Others Groups (WEOG), two. Each has its own electoral norms. An Arab seat alternates between the African and Asian blocs by informal agreement. Turkey and Israel, which has never served on the Security Council, caucus with WEOG.

Subsidiary organs that support the Security Council’s mission include ad hoc committees on sanctions; counterterrorism; nuclear, biological, and chemical weapons; and the international criminal tribunals for Rwanda and the former Yugoslavia. Within the UN Secretariat, the Department of Peace Operations and the Department of Operational Support manage field operations. The Peacebuilding Commission, established in 2005 as a repository of institutional memory and best practices, serves an advisory role.

What are its tools for conflict management?

The Security Council aims to peacefully resolve international disputes in accordance with Chapter VI of the UN Charter, which authorizes it to call on parties to seek solutions via negotiation, arbitration, or other peaceful means. Failing that, Chapter VII empowers the Security Council to take more assertive actions, such as imposing sanctions or authorizing the use of force “to maintain or restore international peace and security.” Peacekeeping missions are the most visible face of the United Nations’ conflict-management work; as of 2025, the Security Council oversees eleven operations across three continents.

The Security Council acted infrequently in the four-and-a-half decades between its founding and the end of the Cold War, often constrained by the U.S.-Soviet rivalry. During that time, it authorized eighteen peacekeeping operations [PDF]. In the post-Cold War period, the Security Council has become more active, greenlighting dozens of peacekeeping operations since the dissolution of the Soviet Union in 1991. Many of these were aimed at responding to failing states, civil wars, or complex humanitarian emergencies, and deploying to conflict zones in the absence of ceasefires or parties’ consent. Under more muscular mandates, they have combined military operations—including less restrictive rules of engagement that allow for civilian and refugee protection—with civilian tasks such as policing, electoral assistance, and legal administration. Developing nations provide the lion’s share of personnel.

However, since Russia’s annexation of Crimea in 2014, tensions have flared between Russia and the U.S. and European members of the P5, leading to concerns that the Security Council is less able to defuse crises. Only two peacekeeping missions, in the Central African Republic and Haiti, have been authorized over the past decade. The 2011 Syrian conflict proved to be particularly difficult to manage, given that Russia—sometimes joined by China—used its veto power [PDF] nearly twenty times to block resolutions aimed at holding the Bashar al-Assad regime accountable for atrocities documented by UN sources. Relations worsened further after Russia invaded Ukraine in 2022, and Moscow has since used its veto power to prevent the passage of several Security Council resolutions condemning the conflict.

Regional organizations have played an increasingly important role in peacekeeping and conflict resolution, in some cases prodding the Security Council to action, and acting as subcontractors on its behalf in others. For instance, the Security Council authorized the use of force in Libya in 2011 after the Arab League called for a no-fly zone, which the North Atlantic Treaty Organization (NATO) then executed. Experts also highlight the increased will and capacity of the African Union, which has partnered with the United Nations in carrying out missions in Somalia and the Darfur region of Sudan.

Despite these partnerships, the council has still sometimes struggled to effectively respond to emerging global crises. During the start of the COVID-19 pandemic in 2020, the Security Council passed Resolution 2532 [PDF], which called for a ninety-day “humanitarian pause” in armed conflicts worldwide, with an exception for conflicts against designated terrorist groups. However, the effect was minimal, with just one conflict party—Colombia’s National Liberation Army—explicitly citing it in an offer to end hostilities.

What sanctions measures are available to the Security Council?

The sanctions provisions in Article 41 of the UN Charter, dormant during much of the Cold War, have become one of the Security Council’s most frequently employed tools. The body had imposed sanctions just twice prior to the fall of the Berlin Wall: In 1966, a trade embargo was enacted against Southern Rhodesia (now Zimbabwe), and in 1977, an arms embargo was enacted against apartheid-era South Africa. The Security Council began to make regular use of sanctions in the early 1990s, starting with Iraq, the former Yugoslavia, and Haiti. There are currently fourteen sanctions regimes in place.

So-called smart sanctions emerged in the mid-1990s as an alternative to what UN Secretary-General Kofi Annan called the “blunt instrument” employed in Iraq following the first Gulf War. These sanctions target discrete economic and political matters and specific individuals deemed threats to international security. Arms embargoes, travel bans, asset freezes, and import/export bans on individual goods, rather than comprehensive embargoes, are now the norm.

But targeted sanctions have raised human rights concerns of their own, and they infrequently result in changed behavior. To be delisted, blacklisted individuals, entities, and items—often those with dual uses, such as agricultural or medicinal applications—require an affirmative vote of sanctions committees, in which all Security Council members are represented. The UN Department of Political Affairs has reported [PDF] that targeted sanctions have been effective in “coercing” states to change their behavior in just 10 percent of cases.

What role does the Security Council play in authorizing military force?

Under the UN charter, members can only use force in self-defense or when they have obtained authorization from the Security Council. However, members and coalitions of countries have often used military force outside of these contexts.

NATO’s seventy-eight-day air war in Kosovo is the most-cited case in arguing for the legitimacy of humanitarian interventions that lack Security Council authorization. After Russia indicated it would block authorization in the Security Council, NATO forces undertook a bombing campaign to protect Kosovar Albanians from ethnic cleansing by Serbs in rump Yugoslavia. An independent commission of scholars later deemed the intervention “illegal but legitimate.”

The emergence of the Responsibility to Protect (R2P) in the early 2000s appeared to justify the use of force outside Security Council authorization by qualifying the principle of noninterference in sovereign affairs. The doctrine, as adopted by the General Assembly in 2005, stipulates that states have a responsibility to protect their populations from crimes against humanity; the “international community” has a responsibility to use peaceful means to protect threatened populations; and when a state “manifestly fails” to uphold its responsibilities, coercive measures should be collectively taken.

Successive U.S. administrations have argued that humanitarian intervention can be legitimate with the backing of regional organizations or “coalitions of the willing.” But Secretary-General Ban Ki-moon rejected this position in 2008, saying, “The responsibility to protect does not alter, indeed it reinforces, the legal obligations of Member States to refrain from the use of force except in conformity with the Charter.” This debate has been revived at various times in recent years, including in the run-up to the 2011 NATO-led Libya intervention and during the Syrian civil war. While Russian officials have at times cited humanitarian intervention as grounds for the invasion of Ukraine, Western analysts say the war is a clear violation of international law.

What criticisms has the Security Council faced?

Many critics, including member states from the developing world, contend that the Security Council’s structure does not reflect current geopolitical realities. Its membership was expanded from six elected members to ten in 1965, and in 1971, the People’s Republic of China took the permanent seat previously occupied by the Republic of China (Taiwan). Since then, the body’s composition has remained unchanged.

Regional powers such as Brazil, Germany, India, Japan, Nigeria, and South Africa have sought to enlarge the Security Council or secure permanent seats of their own. Others have called for France to cede its permanent seat to the European Union in the wake of Brexit, especially after France and Germany decided to share the presidency of the Security Council for two months in 2019. In 2021, Britain announced its support for Germany receiving a permanent seat. And in early 2023, China, France, and Germany called for two permanent seats for Africa on the Security Council. The debate about expansion is often framed as a trade-off between legitimacy and efficacy. Saudi Arabia took the unprecedented step of declining a nonpermanent Security Council seat in 2013, announcing a day after it was elected to a 2014–15 term that it would not serve in the absence of institutional reform.

Other critics of the Security Council include advocates of R2P, who say the veto gives undue deference to the political interests of the P5, leading to inaction in the face of mass atrocities. Russia’s vetoes of Security Council action on Ukraine, for instance, have spurred calls to kick Russia out of the P5. This criticism predates the invasion; Zeid Ra’ad al-Hussein, the UN human rights chief from 2014 to 2018, repeatedly criticized the outsize power of the veto-wielding member states, warning that without institutional change, the United Nations could collapse. 

But it is not just P5 members who have demonstrated reluctance to use force. Aspirants to permanent-member status, including Brazil, Germany, and India, have generally opposed interventions as violations of sovereignty. While R2P advocates criticize the Security Council and its members for a lack of political will, other critics question the United Nations’ conflict-management capacity, often citing 1990s peacekeeping crises in Somalia, the former Yugoslavia, and Rwanda.

In the shadow of its 1993 experience in Somalia, in which eighteen U.S. Army Rangers were killed in an attempt to capture a warlord, the United States was among the powers that prevented a robust UN response in Rwanda. Despite alarming reports received by the Security Council in 1994, it declined to respond as an estimated eight hundred thousand people were killed in a genocide committed against ethnic Tutsis.

The United Nations also suffered humiliating defeats in the Balkans, where peacekeepers were used as human shields in the siege of Sarajevo and failed to protect civilians in the designated safe area of Srebrenica from massacre. Experts say these missions were undermined by both logistical and political problems, including muddled mandates, inadequate resources, and the parochial interests of major powers. In an effort to combat these and other problems, delegates have advocated for more transparency and efficiency in the Security Council’s decision-making process, as well as more interaction with the General Assembly. 

Peacekeeping mandates continue to be scrutinized for their scope, cost, and cases of peacekeeper misconduct. A 2000 self-evaluation, commissioned by Annan and led by veteran envoy Lakhdar Brahimi, said the United Nations had “repeatedly failed,” and would continue to do so absent “significant institutional change and increased financial support.” Peacekeepers deployed to Haiti in the wake of the devastating 2010 earthquake, for example, faced intense criticism for sparking a cholera outbreak that killed approximately ten thousand people between 2010 and 2019.

However, many experts say the United Nations’ overall peacekeeping track record is relatively strong: Recent studies have found that, in general, UN peacekeeping prevents the resumption of violence in post-conflict scenarios.

What are the prospects for reform?

The odds of substantial reform are seen as remote because amending the UN Charter requires an affirmative vote and domestic ratification by two-thirds of UN member states. This includes all of the Security Council’s permanent members, which are unlikely to take measures that would curb their own influence. While there is broad agreement among UN members that the Security Council’s makeup is outdated, each of the various proposals for reform inevitably leaves some aspirants alienated. Some proposals call for additional permanent members and others for a new class of elected seats that have the possibility of renewal. In the absence of charter reform, smaller states have advocated for procedural changes, including greater transparency and closer consultations with troop-contributing countries.

Still, in early 2022, UN General Assembly President Csaba Kőrösi and U.S. President Joe Biden both said that reforming the Security Council should be an important objective. In his 2022 address to the United Nations, Biden urged P5 countries to refrain from overusing the veto and called for enlarging the Security Council, particularly by adding more members from Africa and Latin America and the Caribbean.

In contrast, U.S. President Donald Trump has long been a vocal critic of the United Nations, including its peacekeeping efforts. In February, he criticized the organization, saying “A lot of these conflicts that we’re working on should be settled, or at least we should have some help in settling them. We never seem to get help. That should be the primary purpose of the United Nations.” The Trump administration has positioned itself as skeptical of multilateralism and at times acted as a roadblock to international consensus at the United Nations on issues like Gaza and the extension of certain peacekeeping missions.