State Department’s Diplomatic Security Service Protects Diplomats

  • Days before Russia attacked Ukraine, US Embassy personnel evacuated Kyiv and then from the country.
  • To ensure diplomats are safe in such situations, the State Department has one of the US’s least known but most capable security agencies.

In the weeks and days before the Russian invasion of Ukraine, many focused on the US Embassy in Kyiv and what it was doing to determine the likelihood of a Russian attack.

Although the US intelligence community had been warning of an imminent Russian attack for weeks before the invasion, the US Embassy in Kyiv wasn’t evacuated until a few days before the Russian tanks rolled into Ukraine.

This is the hard reality of the diplomatic life. But to ensure their safety, US diplomats have one of the least known but most capable law-enforcement agencies in the country.

The Diplomatic Security Service

Diplomatic Security Service embassy Niamey Niger

A Diplomatic Security Service security officer, right, in blue plaid, and Nigerian security forces during an exercise at a US Embassy residence in Niamey, April 12, 2018.

US State Department


Created in 1916 as the Office of the Chief Special Agent, the Diplomatic Security Service is the law-enforcement and security arm of the State Department. Joseph Nye was hired as the first Chief Special Agent in late 1917.

With about 2,500 active special agents, the Diplomatic Security Service has four missions: protect US diplomats, perform passport and visa fraud investigations, ensure the integrity of classified US travel documents, and conduct security background checks.

The organization has the largest global reach in federal law enforcement, with offices in 270 locations around the world and 29 US cities.

Every US diplomatic mission operates under a security program designed by the Diplomatic Security Service. These programs are reviewed and maintained regularly to reflect changes on the ground. All US embassies have a regional security officer who reports to the ambassador and is responsible for all security-related matters.

In addition, Diplomatic Security Service special agents work with the US military’s top-tier special missions units.

Diplomatic Security Service terrorist airplane

Diplomatic Security Service trainers simulate a terrorist incident on a plane with US Ambassador-designate to Czechoslovakia Shirley Temple Black, right, in 1988.

US State Department


Special operators from the Army’s Delta Force and the Navy’s Naval Special Warfare Development Group — formerly known as SEAL Team 6 — will often visit US embassies and consulates around the world to review their security and make plans in case of a hostage situation.

Accordingly, US Joint Special Operations Command, which is the national mission force, has detailed plans for every US diplomatic facility in the world.

The Diplomatic Security Service also protects the secretary of state as well as high-ranking foreign dignitaries and officials who visit the US on official business.

While US Marines are assigned to protect US embassies, the Diplomatic Security Service is responsible for protecting people, especially when they are on the move in a foreign country. After the attack on the US consulate in Benghazi, Libya, three diplomatic security officials were ousted from the State Department.

Like the Secret Service, which protects the president and investigates some financial crimes, the Diplomatic Security Service has other roles. One of the more important is conducting security background investigations for the State Department and other federal agencies. The service screens diplomats, civil servants, and other employees to determine their suitability for a security clearance.

Diplomatic Courier

A Diplomatic Courier watches crates being loaded onto an airplane in 2017.

Diplomatic Security Service


Another function of the Diplomatic Security Service is ensuring the integrity of classified US travel documents.

When a US embassy needs to send or receive classified or sensitive material, the State Department uses “diplomatic bags” — which can be any package or container that is properly sealed and identified — that have legal protections from searches by foreign officials.

Any intelligence service worth its salt will try to intercept diplomatic bags and get a look at their contents. This is where the Diplomatic Security Service’s diplomatic couriers come in.

The roughly 100 special agents who are dedicated diplomatic couriers ensure the swift delivery of classified and sensitive materials around the world. They are trained and certified to protect diplomatic bags through a variety of classified techniques.

Selection and Training

Marines State Department Embassy Bucharest Romania

US Marines and State Department officers respond to an attempted security breach during a drill at the US Embassy in Bucharest, February 28, 2015.

US Marine Corps/Sgt. Esdras Ruano


To become a special agent in the Diplomatic Security Service, an applicant must be a US citizen, be willing to deploy overseas, be between 20 and 36 years old, and pass a physical fitness screening. They must also have a four-year degree and obtain a top-secret security clearance.

Those who are selected then face a nearly 60-week pipeline meant to turn them into special agents.

Those who pass the initial screening advance to the Basic Special Agent Course, an intense 29-week selection and training program. Candidates then advance to a three-week orientation, followed by a 12-week federal law-enforcement course.

The pipeline ends with 13 weeks of specialized training, including small unit tactics, tactical combat care, and operational planning.

Diplomatic Security Service Mobile Security Deployments team

Mobile Security Deployment team members secure a street for a motorcade at a Manhattan hotel, September 23, 2018.

US State Department


Experienced special agents can get assigned to the Mobile Security Deployments, a specialized tactical organization tasked with responding on short-notice during times of heightened threats or emergencies domestically and abroad.

MSD agents also assess security at facilities, plan travel routes, and provide counter-assault teams for the US secretary of state and foreign dignitaries.

The State Department relocated most of its people and operations out of Ukraine in the days prior to Russia’s attack. Russia has retreated from Kyiv, and some US diplomats say it’s time to reopen the embassy there, but the Biden administration remains divided over doing so, reflecting concern about security in Ukraine and lingering caution after the Benghazi attack, according to Politico.

When the State Department moves to reestablish that diplomatic presence, the Diplomatic Security Service’s MSD teams will likely be among the first on the ground.

Stavros Atlamazoglou is a defense journalist specializing in special operations, a Hellenic Army veteran (national service with the 575th Marine Battalion and Army HQ), and a Johns Hopkins University graduate.