Former U.S. National Security Advisor Jake Sullivan revealed the reasons behind the prolonged delay in supplying ATACMS missiles to Ukraine

The United States did not initially transfer long-range ATACMS missiles to Ukraine not because of concerns over escalation, but because the Pentagon believed there were not enough of them to even meet potential deterrence needs for the U.S. itself.

This was stated by former U.S. National Security Adviser Jake Sullivan, who served under President Joe Biden, during a speech at a forum at Harvard.

“We didn’t transfer ATACMS at the start because the Secretary of Defense and the military told the President that we didn’t have enough of these systems to meet our basic deterrence needs. They did not recommend transferring them to another country,” said Sullivan.

Later, according to Sullivan, the U.S. managed to produce enough missiles to supply Ukraine with several hundred units. Additionally, over time, U.S. willingness to take risks increased — while in 2022 escalation concerns were taken more cautiously, by 2024 the perception of risk had shifted.

“We learned to make decisions involving higher levels of risk. But overall, even after transferring a large number of ATACMS, we see that they have not become decisive on the battlefield,” the adviser noted.

Sullivan concluded that although there were high expectations surrounding the decision to provide ATACMS, “their impact on the course of the war, based on available data, has not been decisive.”

The Washington Post previously reported that then-U.S. Secretary of Defense Lloyd Austin had declined Ukrainian President Volodymyr Zelensky’s request to make Ukraine a priority in the delivery of ATACMS missiles. Doing so would have required canceling agreements with other buyers and raised concerns, especially given limited stockpiles of munitions for F-16 fighter jets. The U.S. also refrained from sending these missiles due to fears of escalation with Russia and concerns about Russia relocating military targets beyond the missiles’ range.

In October 2024, Sullivan explained that Biden had long resisted sending ATACMS to Ukraine due to the risk of escalation. However, that argument became less relevant after the UK and France supplied Ukraine with their own long-range missiles. The Pentagon also feared that transferring ATACMS could deplete American reserves needed in unforeseen circumstances.

In September 2024, The Financial Times, citing sources, reported that the Biden administration had already decided to provide Ukraine with ATACMS even before Zelensky’s visit to the U.S. but did not announce it publicly to avoid giving the Russian command time to prepare. The transfer was tied to the supply of cluster munitions to Kyiv, specifically cluster warhead versions of the ATACMS.