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US defence budget for 2026: Congress approves continued support for Ukraine and a military presence in Europe

Andrzej Kohut
Jacek Tarociński

On 18 December, President Donald Trump signed into law the National Defense Authorization Act (NDAA) for the 2026 fiscal year, after it received bipartisan support in Congress, passing the House of Representatives by 312 votes to 112 and the Senate by 77 to 20. The annual legislation outlines the detailed budgetary framework for the Department of War (Defense). This year’s bill authorises $901 billion in spending – $8 billion more than the White House had requested. The NDAA represents only one part of the Pentagon’s budgetary process; Congress must still pass an appropriations bill to fund defence spending.

The NDAA for 2026 includes a number of important provisions concerning Ukraine. It allocates $400 million in assistance for the country through the Ukraine Security Assistance Initiative (USAI) and requires immediate notification to Congress should intelligence support to Ukraine be suspended. Under the act, Congress will also receive a detailed report on the threat posed by Russia, including the risks to NATO’s European members. In addition, the NDAA introduces a mechanism that significantly complicates any effort to reduce US troop levels in Europe below 76,000. Furthermore, it allocates funding for the Baltic Security Initiative (BSI) aimed at enhancing the defence capabilities of the Baltic states. However, it contains no explicit provisions for the European Deterrence Initiative (EDI), a far more significant programme that finances the enhanced presence of US forces in Europe, including training and exercises, the prepositioning of weapons and military equipment, infrastructure investments, and initiatives to strengthen the defence capabilities of allied countries.

The NDAA’s provisions indicate that a significant proportion of Republicans in Congress harbour serious reservations about the assumptions underpinning US policy towards Europe as outlined in the latest National Security Strategy (see: ‘The new US National Security Strategy: a manifesto for a sovereign America in a multipolar world’). These concerns relate both to US support for Ukraine and to the US military presence in Europe.

Commentary

  • The allocation of $400 million for military assistance to Ukraine under the USAI for the 2026 and 2027 fiscal years does not guarantee that these funds will actually be used. Congress has merely secured the financial pool; the decision on whether and how the money will be spent ultimately lies with the Secretary of War (Defense). Far more importantly, the NDAA includes a provision that prohibits the Pentagon from classifying weapons and military equipment previously contracted for Ukraine as its own stockpiles and requires that they be transferred to Kyiv (see: ‘America First: US halts arms deliveries to Ukraine’). The USAI’s overall budget remains modest: for comparison, military assistance allocated to the Philippines and Taiwan stands at $1.5 billion and $1 billion respectively.
  • The $175 million in military support for the Baltic states allocated under the BSI carries symbolic weight, but does not enhance the defence capabilities of Lithuania, Latvia, and Estonia in any substantial way. Although the NDAA does not explicitly list the EDI, this does not necessarily signal that the programme will be terminated, as the legislation includes funding for specific infrastructure projects in Europe that have previously been implemented under the EDI framework (see: ‘Consequences of the discontinuation of the Baltic Security Initiative by the Trump administration’).
  • The NDAA introduces certain restrictions on reducing the US military footprint in Europe. It requires the Pentagon to carry out an assessment of the impact on US national security, conduct interagency consultations, and subsequently present the findings to relevant congressional committees if the Department of War (Defense) intends to take any action that could result in: (1) reducing US troop levels in Europe below 76,000 (currently around 100,000) for more than 45 days; (2) relinquishing the position of NATO’s Supreme Allied Commander Europe (SACEUR); or (3) transferring US infrastructure, equipment, and military hardware stationed on the continent. Moreover, the NDAA prohibits any such actions for a period of 60 days following the submission of all required assessments to Congress. Failure to comply with these obligations may lead to a partial suspension of the Pentagon’s budget.
  • The NDAA for the 2026 fiscal year clearly highlights divergences between the Republican-controlled Congress and the Trump administration over the direction of US policy towards European allies. Since the early weeks of the current term, parts of the Republican caucus in Congress have voiced opposition to some of the administration’s plans regarding the US military presence in Europe, particularly relinquishing the position of SACEUR to European allies and reducing support for Ukraine. These critics include influential figures such as Senator Roger Wicker, Chair of the Senate Armed Services Committee. Congress is also increasingly concerned about the erosion of its own role under the new administration. As the campaign for next year’s elections gathers pace, lawmakers are likely to adopt more independent positions. Given its importance and strong bipartisan support, the NDAA offered a useful platform for asserting congressional independence from the White House. In 2020, President Trump vetoed the NDAA, but Congress voted by a large margin to overturn his decision, marking the only successful veto override during his first term in office.