The US is sending tactical ballistic missiles to Ukraine

On September 22, 2023, U.S. officials confirmed that President Joe Biden informed President Volodymyr Zelenskyy that the United States will provide Ukraine with the Army Tactical Missile System. Designated the MGM-140 ATACMS, this extremely powerful weapon is complemented by a long firing range. Additionally, the missile can be fired from the M142 High Mobility Artillery Rocket System previously sent to Ukraine.

Late in the Cold War, the Army identified a need for a long-range conventional missile that could accurately strike enemy reserves deep behind the frontline. Developed during the 1980s, the first operational use of the ATACMS came in 1991 during Operation Desert Storm, where 32 of the missiles were fired. In 2003, during Operation Iraqi Freedom, over 450 ATACMSs were fired.

The ATACMS Block I M39 variant carried 950 M74 Anti-personnel and Anti-materiel bomblets, had a maximum range of 103 miles and used inertial guidance. Equipped with GPS-guidance, the ATACMS Block IA M39A1 variant reduced its payload to 300 M74s but increased its range to 186 miles. In 2022, the Army began updating its existing stockpiles of M39 and M39A1 missiles to the M57E1. Also known as the ATACMS Modification, these GPS-guided missiles replace the cluster munition warhead with a 500-pound WAU-23/B warhead and features a proximity sensor to detonate in the air.

The M48 ATACMS Quick Reaction Unitary missile was the first to replace the M74 bomblets with a single high-explosive warhead. Borrowed from the Navy's A/R/UGM-84 Harpoon anti-ship missile, the 500-pound WDU-18/B warhead was repackaged into the WAU-23/B  for the ATACMS. 42 M48s were fired during Operation Enduring Freedom and the missile remains in service with the Army and Marine Corps. The standard M57 is simply a bespoke version of the M57E1 that old M39s and M39A1s are being updated to and also features the WAU-23/B  warhead.

Previously, supplying long-range missiles to Ukraine was not supported by the U.S. government. "It's our assessment that [Ukrainians] don't currently require ATACMS to service targets that are directly relevant to the current fight," said Undersecretary of Defense For Policy Colin Kohl during a press briefing on August 24, 2022. "You know, we'll obviously continue to have conversations with the Ukrainians about their needs, but it's our judgment at the moment that we should be focusing on GMLRS, not ATACMS." However, the missiles will allow Ukrainian forces to strike Russian positions far behind their defenses.

In FY2022, the unit cost of the ATACMS is approximately $1,476,000. Such an expensive munition also takes time to build and supplying missiles to Ukraine requires depleting current U.S. stockpiles. This raised concern with some U.S. government representatives who opposed sending ATACMS to Ukraine. Due to its high value, the missile's launch container features six circles arranged in a 2x3 pattern like a standard MLRS rocket container despite containing just one missile. This makes it more difficult for enemy forces to target the deadlier and more expensive ATACMS.