CNN  — 

Russia’s invasion has pitted Ukraine against a country with a massive military and one of the world’s biggest economies. Ukraine has been able to keep the fight going in large part due to nearly $350 billion in aid that’s been committed by mostly Western nations since January of 2022.

Now, there are fears the tap may begin flowing less freely — most notably from Kyiv’s most important military backer, the United States.

After a heated spending debate nearly shut down the US government, Congress passed a stopgap funding bill last week that stripped out funding for Ukraine, in an attempt to appease some hardline Republicans.

The move, while not enough for conservatives – who ultimately ousted former Speaker Kevin McCarthy for not cutting spending further – was a blow for Ukraine, which is heavily dependent on Western help to turn the tide of the war. The hundreds of billions of dollars in aid committed already is arriving in various phases over several years, but the counteroffensive aimed at pushing Russia out of Ukrainian territory is entering a critical phase.

To better understand the geopolitical debate behind backing Kyiv, CNN analyzed how international assistance to Ukraine stacks up.

Nearly $100 billion in military aid to Ukraine

Individual countries around the world have committed nearly $100 billion in direct military assistance to Ukraine. Nearly half of that is from the United States, according to data from the Kiel Institute for the World Economy through July 2023.

The US Congress has approved around $46.6 billion in direct military aid to Ukraine since NATO countries began organizing support for Ukraine a month before the full-scale invasion, data shows. This is part of a total $113 billion aid budget for both defense and civilian needs – though not all of it is meant to go directly to Ukraine. Some of those funds are to replenish the US military for its previous donations of weaponry and ammunition and to help other countries impacted by the geopolitical situation.

Collectively, European Union countries have committed $38 billion in direct military support to Kyiv, with Germany, Denmark and Poland the largest contributors. The United Kingdom has pledged more than $7 billion in direct military aid.

Some of the highest-cost military donations include anti-aircraft and anti-ship missiles, weapon-locating radar systems, mine-clearing ships and patrol boats, helicopters, and multiple launch rocket systems, according to the Kiel Institute.

A fair comparison

The US has committed the second-largest amount of money to help Ukraine overall – including military, financial and humanitarian assistance – after the European Union, which has sent a total of around $85.1 billion, according to Kiel Institute data. That figure does not include contributions from individual EU member states, which are counted separately.

But unlike some of Ukraine’s smaller allies, Washington’s contributions account for 0.3% of its GDP, data shows.

Norway and the Baltic states bordering Russia — Lithuania, Estonia and Latvia — are committing a greater proportion of their wealth to the war at more than 1% of their GDP.

That figure includes humanitarian aid – like ambulances, power generators, temporary bridges, family tents and Starlink terminals for satellite communication.

The largest, singular financial contribution from a single country is a $13.4 billion US grant to Ukraine’s government to help with various budgetary and infrastructure needs, including support for Ukraine’s energy security, according to the House Appropriations Committee.

Refugee costs add up for Ukraine’s European allies

When expenses related to hosting refugees are also included in aid calculations, contributions by the European allies who took in the majority of Ukrainian refugees become even more significant. Poland has received the second-largest number of Ukrainian refugees (around 960,000) in allied countries after Germany (nearly 1.1 million), according to data from the United Nations refugee agency in September. Russia also has nearly 1.3 million refugees, the UN data shows.

Around 78% of Poland’s direct support for Ukraine goes to refugee costs – $17 billion out of nearly $22 billion. The country publicly feuded with Kyiv last month over a Ukrainian grains import issue, which has since cooled, though tensions remain.

When factoring refugee costs into GDP calculations, the burden of Poland’s Ukraine aid increases from about 0.7% to 3.2% of GDP, compared to less than 1% for Germany, the Kiel Institute data shows.

The US has allocated $6.6 billion for indirect assistance to Ukrainian refugees as part of its aid package, and as of February had processed around 267,000 Ukrainians into the country through various humanitarian programs since shortly after the war began.

Poland leads in provision of tanks

Thirty-three countries have pledged weapons and military equipment to Ukraine, according to the Kiel Institute. Several others have offered training and other indirect military assistance.

The number of tanks Poland has committed to Ukraine is unmatched by any other country — a total of 324, data shows. The US has given less than a quarter of this number.

But the US leads in assistance with heavy weapons and accompanying ammunition, as well as in supplying light infantry, with at least 150 million units of ammunition pledged. The country is supplying 38 multiple launch rocket systems along with ammunition, and 270 Howitzer artillery weapons. Both have proved effective on the front line, Ukrainian officials have said.

At least 35 anti-aircraft surface-to-air missile systems have also been committed to Ukraine by the US — the most of any country, and the total amount is likely higher as some quantities have not been disclosed.

Joshua Berlinger contributed to this report.