MAY 2025
Can Ukraine Fight
Without U.S. Aid? Seven
Questions to Ask
By Iselin Brady, Daniel Byman, Riley McCabe, and Alexander Palmer
T
he Trump administration has repeatedly threatened to walk away from Ukraine if there is
no progress on a peace deal between Ukraine and Russia. Although the administration has sent
mixed signals, its threat is not empty. On March 3, 2025, the United States suspended military
aid and intelligence sharing to Ukraine following a tense meeting between President Trump and
President Zelensky on February 28, only lifting the suspension on March 11.
A U.S. suspension of military support to Ukraine would be a grievous blow to Kyiv. But would it be fatal?
Ukraine’s own resolve has been formidable even after three years of war, and Europe, which already
provides tens of billions of euros in nancial and military aid, might play a still greater role. This paper
argues that a complete U.S. military and intelligence aid cuto would signicantly harm Ukraine’s ability
to ght Russia but would not necessarily lead to immediate defeat—and that more limited cutos would
have more limited eects on Ukraine’s battleeld performance. But the exact extent to which a U.S.
cuto would harm Ukraine depends on Europe’s ability to ll the gap with its own capabilities. Ukraine
currently relies heavily on U.S. systems, training, intelligence, and logistics, and although European
support and Ukraine’s own defense industry are substantial and growing, they cannot fully replace U.S.
capabilities—particularly in the areas of air defense and intelligence assistance for precision targeting.
The result is that continued U.S. aid remains extremely important for Ukraine’s long-term eectiveness
on the battleeld. The broader geopolitical implications of a U.S. withdrawal could embolden Russia
and its allies while straining transatlantic unity.
Understanding the true impact of a cuto, however, requires a deeper understanding of the types of
weapons involved, European and Ukrainian capabilities absent the United States, and how China and
other Russian allies would respond. The responses to the seven questions below illustrate the impact
