What is Trump’s decision about?

Supplies of equipment, weapons, and ammunition from the United States are to be suspended until the Ukrainian authorities have demonstrated—in the opinion of the U.S. administration—their willingness to negotiate with Russia to end the war. The suspension will include deliveries from U.S. military stocks permitted under the Presidential Drawdown Authority (PDA). The last such shipments were authorised by the Joe Biden administration just before he left office. Although around $3.85 billion allocated under the PDA by Congress last year remain available, the Trump administration has not announced any new support packages. The purchase of U.S.-made equipment and weapons for Ukraine under the Ukraine Security Assistance Initiative (USAI) is also to be suspended, although it is unclear whether this applies only to deliveries not yet contracted or also to the termination of contracts already signed with U.S. companies. The Trump administration had already halted smaller purchases supported by U.S. grants and loans under the Foreign Military Financing (FMF) programme as part of the overall suspension of U.S. foreign aid.

Some media also report that aid in the form of intelligence and reconnaissance has also been stopped. The same may apply to assistance in terms of communications, radio-electronic warfare, cyberdefence, training of Ukrainian soldiers, and the participation of U.S. personnel in coordinating support for Ukraine within NATO.

What is Trump’s motivation?

Trump’s decision is in line with his claims that U.S. military support discourages Zelensky from entering peace talks with Russia. The Ukrainian president, in turn, argues that agreements with Russia will not be effective without Ukraine receiving strong security guarantees, especially from the United States. These differences led to a stormy discussion between the two leaders during a meeting at the White House on 28 February and the non-signing of an agreement on the exploitation of Ukrainian mineral deposits, including rare earths, by U.S. companies. The suspension of military aid is to be a direct consequence of this incident.

Trump wants to force Zelensky to quickly negotiate a ceasefire and peace agreement for several reasons, even if it means making major concessions to Russia. During his election campaign, Trump promised an immediate end to the war, while gaining access to Ukrainian raw materials would be supposed compensation to the U.S. for the costs of supporting Ukraine, which he claimed were too high, especially in comparison with the aid from European countries. Ending the conflict is also important for the Trump administration as a key element in improving relations with Russia. This is intended to pull Russia away from China, which the U.S. sees as its main rival. Trump administration officials have also signalled that the end of the fighting in Ukraine will be followed by a reduction in the U.S. military presence in Europe. The saved funds are to be used to strengthen deterrence of China in the Indo-Pacific.

What does the suspension of U.S. military assistance mean for Ukraine?

The suspension of U.S. military aid will significantly hamper Ukraine’s capabilities to defend against Russia. According to the NATO estimates, the U.S. accounted for 40% of total support in 2024, while European allies and Canada accounted for 60% (combined, totalling more than €50 billion). The effects of the suspension of supplies of equipment, weapons, and ammunition could be felt in just a few months. Russia then could make further progress along various parts of the front, and its air and missile strikes could become more damaging as air defence assets dwindle. The effects of the suspension of other types of U.S. support, in particular in the fields of intelligence, reconnaissance, communications, electronic warfare, and cyberdefense, would be felt sooner. In these areas, Ukraine is particularly dependent on the U.S., as they largely enable Ukrainian troops to maintain situational awareness at the strategic level.

Trump’s decision may further reduce Ukraine’s ability to launch local counter-offensives, already limited by a shortage of trained manpower. Ukraine also may not count on a U.S. contribution to “capabilities coalitions” of the so-called Ramstein Group in the field of artillery (supplies of howitzers) and aviation (i.e., F-16 multi-role jet fighters). However, most acute for Ukraine might be the shortage of interceptors for Patriot air and missile defence systems, 155 mm artillery ammunition, and GLMRS rockets for the HIMARS and MRLS launchers. The U.S. decision may also exclude any prospects for future deliveries of American armoured vehicles (Abrams tank, Stryker, Bradley, M-113), despite huge reserves at the disposal of the Pentagon. Ukraine probably will be forced to cannibalise some of the U.S. equipment for spare parts.

What are the implications for Europe?

The survival of Ukraine as a sovereign state is a vital interest for the EU and its partners, and as such they will be forced to significantly increase their military assistance to prevent Russia from achieving victory or Ukraine from capitulating. Nevertheless, Europe will not be able to fill all the capability gaps created by a halt to U.S. assistance, especially in the immediate to short term. Increased support in the areas of satellite intelligence and reconnaissance may be urgently needed, and, among other things, it will be necessary to use still existing strategic reserves of ammunition and interceptors held by European and other partners of Ukraine. Of equal importance is also the need to provide Ukraine with more long-range offensive missiles, such as the German Taurus, Norwegian NSM, or Swedish RBS-15.

In the longer term, the need to increase assistance to Ukraine will require more military spending by the European NATO states and investments in the production capacity and technological base of the European defence industry, which has been just announced by the President of the European Commission Ursula von der Leyen under the “ReArm Europe initiative.

In political terms, the U.S. decision may cause an unprecedented crisis in transatlantic relations and would be especially serious if the Trump administration starts to pressure European states (including Poland) to reduce or suspend support for Ukraine.