What Are ATACMS Missiles, the U.S. Missiles That Officials Say Ukraine Fired Into Russia?

 In a major policy shift, the Biden administration has authorized Ukraine to use the ballistic missiles within Russia.

A U.S. Army Tactical Missile System, known as ATACMS, is shown in a photo provided by South Korea’s Joint Chiefs of Staff. Credit...South Korea’s Joint Chiefs of Staff, via European Pressphoto Agency

Ukraine’s military used American-made ATACMS missiles to strike into Russia for the first time on Tuesday, according to senior U.S. and Ukrainian officials, nytimes.com.

Two days earlier, the Biden administration had authorized Ukraine to use the U.S.-supplied ballistic missiles for attacks inside Russia for the first time, in a major policy shift.

The ballistic missiles are known as the Army Tactical Missile Systems, or ATACMS (pronounced “attack ’ems”).

Ukraine has been lobbying the United States for years to receive the authorization, which comes in the final months of the Biden administration. President-elect Donald J. Trump has said he will seek a quick end to the war in Ukraine.

What do these missiles do?

ATACMS, made by Lockheed Martin, are short-range ballistic missiles that, depending on the model, can strike targets 190 miles away with a warhead containing about 375 pounds of explosives. Ballistic missiles fly much higher into the atmosphere than artillery rockets and many times farther, coming back to the ground at incredibly high speed because of gravity’s pull.

They can be fired from the HIMARS mobile launchers that the United States has provided Ukraine, as well as from older M270 launchers sent from Britain and Germany.

ATACMS are often referred to as “long-range missiles,” but that is a subjective term. They can reach further into Russia than any other Ukrainian missile, but cannot travel as far as a cruise missile or intercontinental ballistic missile.

The ATACMS missile was developed in the 1980s to destroy high-value Soviet targets deep behind enemy lines. It was built as a rare guided weapon at a time when the United States mainly relied on “dumb bombs” and other unguided munitions.

Today, the Pentagon has two versions of the ATACMS in its inventory: a cluster weapon and one that carries a single explosive charge.

What happened in Ukraine’s airstrike?

Russia’s Ministry of Defense said in a statement that Kyiv used six ATACMS on Tuesday. It claimed that five of the missiles were shot down and another was damaged, saying that falling fragments caused a fire at the military facility but there were no casualties.

The Ukrainian military said it struck a large ammunition depot in the Bryansk region of Russia before dawn, but did not specify the weapon used. The Ukrainian official who spoke on the condition of anonymity confirmed the use of ATACMS.

The attack came on the same day that President Vladimir V. Putin lowered Russia’s threshold for the use of nuclear weapons, a long-planned move whose timing appeared aimed at showing the Kremlin could respond aggressively to Ukrainian strikes on Russian territory with American long-range missiles.

Why did the U.S. wait?

The decision about whether to arm Ukraine with ATACMS has been a sensitive subject since Russia’s invasion of Ukraine in February 2022. Since early in the war, President Volodymyr Zelensky of Ukraine has pleaded for weapons that can hit even deeper into Russian-held territory, and eventually into Russia itself.

The United States supplied Ukraine with ATACMS last year, but the Biden administration had until now withheld its approval for their use across the border into Russia.

The White House has been concerned that if Ukraine used the missiles to strike targets deep inside Russia, President Vladimir V. Putin might respond by escalating.

“We’re trying to avoid World War III,” President Biden has said.

Some Pentagon officials had also opposed giving these missiles to the Ukrainians because of limited supplies.

Mr. Zelensky says this kind of weapon is crucial to his country’s ability to launch a wider counteroffensive and has insisted that he has no plans to strike Russian cities or target civilians.

On Sunday, he suggested in a nightly address that the U.S. restriction had been lifted without confirming it, saying: “Such things are not announced. The rockets will speak for themselves.”

How will Ukraine use them?

In addition to strikes inside Russia, U.S. officials said Ukraine may use ATACMS to support Ukrainian troops against Russian and North Korean forces in the Kursk region of western Russia.

The Russian military is preparing to launch a major assault by an estimated 50,000 soldiers, including North Korean troops, on dug-in Ukrainian positions in Kursk with the goal of retaking all of the Russian territory that the Ukrainians seized in August.

The Ukrainians could use the ATACMS missiles to strike Russian and North Korean troop concentrations, key pieces of military equipment, logistics nodes, ammunition depots and supply lines deep inside Russia. That could help the Ukrainians blunt the effectiveness of the Russian-North Korean counteroffensive.

Last year, President Biden agreed to supply several hundred ATACMS for use on Russian-held Ukrainian territory, including the Russian-occupied Crimean Peninsula. So it is unclear how many of the missiles the Ukrainians have left in their arsenal to use in the Kursk region.

Has the U.S. used them in combat?

Yes. The U.S. military fired around 30 ATACMS in 1991 during Operation Desert Storm, according to government records. They were used to strike Iraq’s medium-range ballistic missile launchers and surface-to-air missile sites.

Those first-generation cluster munition versions could fly about 100 miles. Once over their targets, they released 950 bomblets.

The Army also fired more than 400 of the bomblet-carrying tactical missiles in Operation Iraqi Freedom, according to government records, most notably in the early hours of the 2003 invasion.

The Pentagon later restricted the use of cluster munitions because they often failed, littering battlefields with hazardous duds that killed and wounded soldiers and civilians after combat ended. The Army refurbished many of the early ATACMS in the 2000s and replaced the bomblets with a single explosive warhead.

Marc Santora and Maria Varenikova in Kyiv and Lara Jakes in Rome contributed reporting.

John Ismay is a reporter covering the Pentagon for The Times. He served as an explosive ordnance disposal officer in the U.S. Navy. More about John Ismay

Ephrat Livni is a reporter for The Times’s DealBook newsletter, based in Washington. More about Ephrat Livni