Luigi Scazzieri / Jun 2025
Photo: Shutterstock
Donald Trump’s election as US President has led to a flurry of diplomacy over Russia’s war on Ukraine. The outcome remains unclear: there may be a settlement, continued fighting, or a brief ceasefire followed by a resumption of hostilities. What is clear, however, is that Ukraine will need military support for the long-term, to defend itself against ongoing Russian attacks or deter a new round of fighting. At the same time, the Trump administration is highly unlikely to fund additional US military support to Ukraine. Adjusting to this new reality will be hard for Europe. But Europeans can use a range of mutually reinforcing strategies to put Ukraine in the strongest possible position.
The cost of US disengagement
In financial terms, the US has allocated almost €65 billion in military support since 2022, while the EU has provided over €51 billion, with the UK and Norway providing an additional €12 billion. Estimates based on assistance provided in 2024 suggest that Europe would only need to increase its support by 0.12% of GDP to make up for the loss of all US military support. But financial support is just one consideration, and the size of the gap depends on whether Washington is willing to continue providing Ukraine with military capabilities paid for by Europeans, or whether there is a complete halt in all deliveries of American equipment to Ukraine and a full cut-off in critical intelligence support provided by the US.
A complete loss of US support would leave a hole significantly larger than the numbers alone suggest. First, US equipment accounts for a very high proportion of overall assistance to Ukraine in many weapons categories, such as rocket artillery (98%), howitzer ammunition (80%) and long-range air defence systems (80%). Ukraine depends on Washington to provide a consistent supply of spare parts to keep US-origin equipment operational.
Secondly, the US provides Ukraine with communications and intelligence support that is crucial but difficult to quantify. In terms of communications, Ukraine has so far relied on Starlink’s 40 000 terminals in the country to provide its forces with real-time connectivity critical for drone operations. In terms of intelligence, data from US satellites and other surveillance assets has allowed Kyiv to accurately and quickly track Russian troop movements, fend off air attacks and hit Russian assets far behind the frontlines, disrupting logistics, communications and production.
For some of these weapons systems there is a European alternative. Europeans have comparable capabilities to the US in terms of howitzers, artillery ammunition and battle tanks. The main challenge is scaling up production to meet operational demands. The most challenging gap for Europeans to fill in a scenario where the US completely cut off all assistance to Ukraine would be providing Kyiv with communications and intelligence support. Intelligence, surveillance and reconnaissance have long-been recognised as critical shortfalls for Europe. It would also be very challenging for Europe to provide a like-for-like replacement for the US in terms of the quantity and quality of data gathered and the speed with which it is processed, analysed and passed onto Kyiv.
How Europeans can respond
The scale of the challenge facing Europeans depends on exactly what stance the US takes. A full cut-off of US arms and intelligence assistance is not certain. While the Trump administration is unlikely to fund more direct military support to Ukraine, deliveries of aid committed under the Biden administration are set to continue for years. Moreover, even once that assistance runs out, Washington may still be willing to provide Ukraine with specific capabilities if Europeans pay for them.
Europeans can use a range of strategies to keep Ukraine supplied. First, boosting Ukraine’s domestic production capacity should be a core element of Europe’s strategy both immediately and over the long term. Since the start of Russia’s full-scale invasion in 2022, Ukraine has greatly increased its domestic production capacity, both in terms of quantity and quality of military equipment. Kyiv is now recognised as a leader in many areas, especially drones. Since last year, Europeans have been buying equipment for Ukraine directly from Ukrainian industry – through the so-called Danish model. The EU itself has directed a €1.4 billion share of the profits from Russia’s frozen assets to supporting Ukraine’s defence industry. Production in Ukraine is much cheaper and faster than in the EU, and the equipment is adapted to the needs of Ukraine’s forces. Moreover, Ukraine’s defence sector has substantial spare capacity: according to Ukraine’s defence minister, more than half of the country’s defence industrial capacity is currently unused.
There is a strong case for Europe to increase its investment in Ukraine’s defence industry to ensure that Ukraine’s capacity is fully utilised and to help modernise the Ukrainian defence industry. Deepening existing cooperation between European defence firms and Ukraine should be encouraged, as should Ukraine’s integration into the European Defence Industrial Base.
Second, Member States could accept a higher degree of risk in terms of the stocks of military equipment that they hold in reserve. For example, countries geographically distant from Russia and facing a low likelihood of direct attack could re-assess their immediate requirements regarding stocks of ammunition or air defence interceptors. As long as Russia is fighting in Ukraine, an attack on a European country remains very unlikely.
Third, Europeans should try to avoid an extremely damaging withdrawal of US support for Ukraine. The EU should attempt to secure equipment and spare parts for Ukraine from the US, by purchasing it from Washington on Ukraine’s behalf or by giving Ukraine funds to do so itself. Buying equipment from the US would minimise operational disruption for Ukraine. Notably, there are signs that the US may be more open to such an approach after the signing of the minerals deal with Ukraine. Following the deal, the Trump administration approved several sales of military equipment to Ukraine and authorised Europeans to transfer US equipment from their stocks to Kyiv.
Fourth, Europe needs to invest in strengthening its domestic defence production. This is a medium-to long-term undertaking: while Europeans often produce high-quality equipment, it is typically manufactured in small quantities and slowly. Recent increases in defence spending across much of Europe should translate into more orders from industry and higher production rates for key equipment. Increasing production, especially of air defence and long-range strike capabilities, should be a political priority. Europeans need to place large long-term joint or coordinated orders to consolidate demand and send a strong, clear signal to industry to invest in new production lines. There is a strong case for aggregating orders with close partners such as the UK, given the level of integration between EU and British industry in sectors like air defence and long-range strike.
Finally, Europeans also need to make substantial investments to address the most critical capability gaps, particularly in terms of communications and intelligence. Again, this will require them to expand their existing intelligence gathering and processing capabilities. But there are also actions that Europeans can take in the immediate term to better integrate their existing capabilities, for example by better coordinating the coverage of their satellite fleets.
Supporting Ukraine is a long-term challenge for Europe, and making up for a steep reduction in US support will be difficult. Europeans should pursue a set of mutually reinforcing strategies to keep Ukraine supplied, including purchasing equipment for Kyiv from the US, ramping up production in Europe and Ukraine, and rapidly investing in missing capabilities. None of this will be easy, but a Ukrainian defeat would be catastrophic for Europe’s security.
The full commentary on which this oped is based can be found on the EUISS website.
