How Trump’s threats to abandon Ukraine war pose battlefield conundrums for Kyiv

LONDON — President Donald Trump — frustrated by the failure of his diplomatic efforts to date — has raised the prospect of entirely abandoning U.S. engagement in Russia’s 3-year-old invasion of Ukraine.

“Sometimes you see two young children fighting in the park,” Trump said in June about the ongoing war, which is the largest armed conflict in Europe since World War II.

“Sometimes you’re better off letting them fight more before you pull them apart,” the president added — his remarks the latest in several months of public skepticism over the U.S. continuing to back Ukraine.

In practice and rhetoric, American aid to Ukraine appears to be drying up. The administration approved a $50 million sale of military aid to Ukraine in April, but only after Kyiv signed off on a controversial minerals sharing deal. But the White House is also yet to dip into some $3.9 billion earmarked to fund military aid to Ukraine — to be drawn from existing U.S. stocks, meaning it can be delivered quickly — that Biden was not able to spend before the end of his term.

It would be Russia that would benefit from a permanent halt to U.S. aid, Ukraine has warned.

“Without American weaponry, the situation on the battlefield will of course be more difficult,” Oleksandr Merezhko, a member of the Ukrainian parliament representing President Volodymyr Zelenskyy’s party and the chair of the body’s foreign affairs committee, told ABC News.

Zelenskyy said early this year that American aid accounts for 30% of Ukrainian weaponry. Though other estimates go as low as 20%, it is clear that Washington remains a key benefactor.

A nine-month pause on U.S. aid in 2024, due to a gridlocked Congress, forced Kyiv to consider a future without American assistance. Those fears materialized in March 2025 when Trump imposed a week-long freeze on all American military aid and intelligence sharing with Ukraine.

The flow soon resumed, but Trump’s frustration has only deepened as U.S.-brokered peace talks floundered.

The costs of war

The U.S. remained the most generous single contributor of aid to Ukraine as of April 2025, according to the Kiel Institute for the World Economy, a research group based in Germany that tracks support from foreign governments toward Ukraine.

The U.S. has contributed around $130 billion in total aid to Ukraine since 2022, of which $74 billion is military assistance. Combined, European Union nations have contributed more overall — $157 billion — but less than the U.S. on the military front, at slightly less than $73 billion.

Ukraine’s budget for military and security spending approved by lawmakers in late 2024 was around $53.7 billion.

Oleksandr V. Danylyuk, an associate fellow at the Royal United Services Institute think tank in the U.K., told ABC News that American military assistance is important but not vital.

“I wouldn’t underestimate it, but I wouldn’t overestimate it either,” he said. Around half of American weapons systems and ammunition provided could be replaced by alternatives, he said.

How to find replacements for weapons the U.S. would withhold may be the most salient question, Pavel Luzin — an analyst at The Fletcher School of Law and Diplomacy at Tufts — told ABC News.

“The previous administration decided that the American taxpayers should” shoulder the burden, he said. “The current administration wants to share this burden.”

“Europe can pay for the American arms for Ukraine and it has enough money for this,” Luzin said. “Ukraine also can pay for the arms using long-term European and/or American loans. Even the Russian frozen assets could be used for this purpose.”

Europe has been criticized for its slow mobilization of its vast resources. But Tina Fordham, a geopolitical strategist and the founder of Fordham Global Foresight, told ABC News, “I think we saw during the during the pandemic, for example, and after the Russian invasion, that Europe is initially slow to act, but then it can act decisively.”

‘There will be more civilians dying’

Perhaps the most vital single U.S. weapon system now in Ukrainian hands is the Patriot surface-to-air missile system, which has proven its value in downing drones, ballistic missiles and Russian aircraft since arriving in the country in the spring of 2023.

Ukraine now fields at least six Patriots, two of which were provided by the U.S. and the others by different NATO allies.

Ukraine has other air defense platforms — among them the European IRIS-T and SAMP-T systems — but none have been so publicly celebrated by Ukraine for blunting Russian attacks. The system, which entered U.S. service in the 1980s, has even been able to shoot down Russian hypersonic missiles.

Zelenskyy said this month that his nation needs to “urgently” strengthen its air defense capabilities in response to Russia’s intensifying missile and drone attacks on cities nationwide.

“We urgently need positive signals from the United States — concrete signals regarding air defense systems,” he said. “We are still waiting for a response to our request to purchase systems that can help — concrete signals, not words.”

Danylyuk said air defense is one area in which American support is particularly key.

American-made defenses help enhance Kyiv’s security in particular, he said. Without them, “Kyiv would be hit in the same way as Odesa or Zaporizhizha,” Danylyuk said.

“That’s not nice. It will make life — especially for Western diplomats including the U.S. diplomats — much worse,” he continued. “Will it change our will to fight? No. There will be more civilians dying, that’s the only difference.”

Behind and far above the front line, America’s enormous intelligence capabilities have also been helping Kyiv resist Russia’s war. American reconnaissance flights over eastern Europe, for example, have offered Kyiv otherwise unattainable forewarning on Russian activity and assistance in targeting.

The Center for Strategic and International Studies said in May that U.S. intelligence aid has been “extensive,” including signals, imagery and human intelligence. “This support has enabled Ukraine to counter missile barrages, disrupt covert operations and track force movements,” CSIS wrote.

Notably, Ukraine’s air raid alerts are heavily informed by U.S. satellite data. When intelligence sharing was frozen in March, Ukrainian politicians warned that the result would be more dead civilians from Russia’s nightly barrages.

Shell hunger has also been a major problem for both sides throughout the war. Russia has turned to North Korea and Iran for sustenance, while Ukraine has turned to the West. During President Joe Biden’s term, the U.S. sent more than 3 million 155mm shells to Ukraine. Any loss of supply could prove deadly for frontline Ukrainian units.

America in retreat?

The disappearance of other weapons from the battlefields would serve as a potent signal of an American pivot.

Kyiv relies on the U.S. for ammunition for the HIMARS rocket artillery system, for example, including the long-range ATACMS.

British-French Storm Shadow/SCALP cruise missile, Ground Launched Small Diameter Bombs, M777 howitzers, AGM-88 HARM anti-radiation missiles and F-16 fighter jets are all systems either produced by the U.S. or relying on American components and systems — thus giving Washington power to veto their transfer to Kyiv.

An end to American aid, Danylyuk said, “Would create some problems,” though would not “be a complete disaster” if Kyiv is able to quickly source replacements.

Regardless, “Ukraine is not going to collapse,” Danylyuk said, recalling the two past windows during which American aid flows froze over.

“We could survive that terrible nine months without U.S. aid. So, it’s not like Ukrainians are going to surrender.”