Rep. Elise Stefanik, R-N.Y., will testify before the Senate Foreign Relations Committee on January 16, 2025, as part of her confirmation process to become the next U.S. ambassador to the United Nations.

International diplomacy is the essence of the United Nations As a former United Nations official and a scholar who has published extensively at the United Nations, I know that diplomacy is an art, not a science.

A good ambassador can make a real difference.

Direct line from the United Nations to the President

The alliances that nations form and sustain at the United Nations are necessary to help respond to global crises that exceed the influence and power of any single nation.

All 193 governments that make up the United Nations have ambassadors responsible for negotiating different UN agreements on issues ranging from terrorism to nuclear proliferation.

Of all these ambassadors, the position of special envoy to the United States is a particularly high-profile and unique one. First, the United States hosts the United Nations Headquarters. The United States is also the largest financial contributor to the United Nations.

Some U.S. ambassadors have been career diplomats, such as current Ambassador Linda Thomas-Greenfield, who was appointed by President Joe Biden in February 2021.

Other former U.S. ambassadors to the United Nations have backgrounds in other fields, including academia, journalism and U.S. politics.

U.S. ambassadors may be members of the President's Cabinet, reporting directly to the President, or they may not have Cabinet ranks and report to the Secretary of State. Nikki Haley, who served as ambassador to the United Nations during Trump's first administration, has Cabinet status and will, assuming Stefanik is confirmed, also.

Hearing the president's opinion can enhance an ambassador's influence at the United Nations

ambassador's highest position

U.S. ambassadors are effective international advocates for their government's interests, whether reducing food insecurity and preventing famine in other countries or trying to prevent North Korea from launching ballistic missiles.

The ambassador explains the U.S. government's special position to other countries' ambassadors and representatives to the United Nations

The U.S. ambassador also hears the political positions of foreign representatives. The ambassador then serves as a bridge between the United Nations in New York and the U.S. government in Washington, guiding difficult conversations about issues such as human rights and terrorism.

The ambassador's third day-to-day responsibility is to oversee the 150 State Department personnel and other staff at the U.S. Mission to the United Nations, a building on First Avenue in Manhattan across the street from U.N. headquarters.

Staff at the U.S. mission do everything from negotiating Security Council resolutions to advising ambassadors and other top officials on media relations.

The U.S. ambassador is also actively involved in the election of the United Nations Secretary-General, who leads the organization's various political and humanitarian efforts during his five-year term.

Countries can nominate specific candidates to serve as Secretary-General. But any candidate would have to be able to win the support of the United States and other permanent members of the Security Council, who have the power to shoot down and reject potential U.N. leaders.

Countries will vote to appoint a new secretary-general in 2026.

United Nations Security Council

The majority of the U.S. ambassador's work is conducted in the Security Council, an important component of the United Nations whose mission is to maintain international peace and security. Since the founding of the United Nations in 1945, the Security Council has been driven almost entirely by crises and emergencies.

The council's powers are arguably greater than any other branch of the United Nations, as its recommendations and decisions (called resolutions) are considered binding under international law. The council has voted on sanctions - which could look like travel bans or freezes on international assets - targeting a range of individuals, countries such as Iran and Somalia, and terrorist groups such as al-Qaeda. It also has the power to authorize the United Nations to deploy peacekeeping operations to conflict areas.

The United States, China, France, Russia and the United Kingdom are the five permanent members of the Security Council. When other countries take turns participating in the work of the Security Council, only permanent members can veto resolutions, leading to frequent deadlocks.

In 2024, the United States used its veto power five times to veto resolutions on the war between Israel and Hamas.

The U.S. ambassador can help decide which issues the Security Council discusses, draft and share resolutions, and influence how other Council members vote.

Real negotiations take place not in formal meetings that are routinely broadcast live, but in informal consultations behind closed doors. This is where diplomats use their ingenuity and resolve differences.

Days after the 9/11 terrorist attacks on the World Trade Center and the Pentagon, U.S. Ambassador John Negroponte, appointed by then-President George W. Bush, negotiated a resolution calling on governments to adopt different counterterrorism activities .

Six months after the U.S. Senate confirmed Susan Rice as ambassador in 2009, she led the Security Council in approving a resolution imposing economic sanctions on North Korea in response to its nuclear and missile tests.

Today, the Security Council is dealing with conflicts in Africa, Asia, Europe and the Middle East. The committee also focuses on counterterrorism, energy, climate, natural resources and other issues.

Case study

The U.S. ambassador to the United Nations is a public figure who is expected to travel abroad frequently to illustrate the importance of U.S. participation and leadership in the United Nations.

This is important because by 2023, approximately 40% of Americans will say that the United States has not benefited from membership in the United Nations. And in democracies, successful foreign policy approaches must have public support.

This story is part of a series of profiles on cabinet and senior executive positions.