In a new assessment, the Institute for the Study of War (ISW) warns that suspending military assistance to Ukraine would significantly weaken America’s negotiating position and potentially tip the battlefield in Russia’s favor.

Following a heated meeting between US President Donald Trump and Ukrainian President Volodymyr Zelenskyy on 28 February, the Trump administration is reportedly considering halting military aid to Ukraine; however, this decision has not yet been approved. 

The Oval Office meeting, intended to discuss a US-Ukraine mineral agreement in exchange for aid, devolved into a contentious exchange, leading to the cancellation of the agreement’s signing and the Ukrainian delegation’s departure from the White House. 

President Trump accused Zelenskyy of “gambling with World War III” by not pursuing peace talks and criticized him for refusing to make concessions to Russia. The Ukrainian president maintained that any ceasefire would require security guarantees to ensure Russia’s compliance, highlighting previous ceasefires that Russia had not honored.

The US has allocated over $65.9 billion in support for Ukraine since the invasion began, becoming the largest provider of military aid to Ukraine. The Ukrainian President himself emphasized that Ukraine would not be able to win the war without US support.

The ISW emphasizes a clear correlation between Russian territorial gains and interruptions in Western support. When aid slowed in the spring of 2024, Russia was able to exploit the situation and make advances. The current steady flow of Western assistance has been crucial in slowing Russian progress along the front lines and disrupting Russia’s defense industrial base.

Ukrainian forces have successfully leveraged US-supplied systems, including Patriot air defense and HIMARS long-range strike capabilities, to inflict “unsustainable losses on Russian forces while holding them to marginal gains.” 

This military pressure, combined with Russia’s mounting economic and force generation challenges expected in 2025, gives the United States significant leverage in peace negotiations.

“A suspension of ongoing US military assistance to Ukraine would encourage Russian President Vladimir Putin to continue to increase his demands and fuel his conviction that he can achieve total victory through war,” the ISW states in its analysis.

The ISW also highlights broader geopolitical implications, noting that curtailing Ukraine aid “would risk diminishing US influence in the world and emboldening US adversaries,” such as Iran, North Korea, and China.

Putin continues to rely on Iranian drones and North Korean missiles and troops in the Russo-Ukrainian war.

US support for Ukraine represents “a demonstration of the United States’ commitment to defending democracies against ongoing and future aggression around the world.” 

The institute warns that America’s adversaries would interpret Ukraine’s abandonment as a sign that the US might similarly abandon other allies, potentially leading to further testing of US commitments globally.