The 2026 National Defense Authorization Act: What Europeans Need to Know

The US House just passed the final negotiated text of the 2026 National Defense Authorization Act (NDAA). In this annual defense bill, which covers the US fiscal year (FY) 2026 (Oct 2025–Sept 2026), Congress outlines its defense policy priorities and authorizes the Pentagon to carry out its defense mission. Through the NDAA, Congress determines how the executive branch, including the Pentagon, may spend money, creates reporting requirements to ensure money is spent responsibly, and adjusts US domestic law to support defense priorities. Historically, the passage of the NDAA is a broadly bipartisan effort that signals alignment and continuity on defense priorities across the US government—including support for allies and partners in Europe.

This year’s NDAA is particularly noteworthy because it arrives just after the White House has released its own National Security Strategy (NSS)—one that seeks to significantly shift US priorities away from Europe and toward the Western Hemisphere. Yet, in contrast to the political priorities laid out by the new NSS, the staunch support for Europe demonstrated in the legally binding 2026 NDAA signals a plurality of viewpoints on European security in Washington—and even in the Republican party. US policy is likely to sit between the politically meaningful but nonbinding NSS and the legally binding but more moderate NDAA. Congressional leaders—including Republicans—are pointing to opportunities for European leaders to cooperate with the United States on defense issues. With the House passing the final bill, here are the key points that European audiences should take away:

Support for NATO remains strong in Congress

The NDAA bolsters support for NATO and European allies, providing a message of solidarity in a moment of waning support from the US administration. Congress is still a strongly pro-NATO legislative body with bipartisan alignment on transatlantic security issues. While echoing the administration’s call for greater burden-sharing and oversight over allies’ implementation of their commitment to higher defense spending agreed at the 2025 NATO Hague summit, this year’s NDAA constrains potential administration efforts to move troops away from Europe and shift strategic focus away from Russia. The bill contains provisions that prohibit a reduction of US forces below 76,000 troops on the continent without first providing Congress with a certification of consultation with NATO allies and independent assessments of the impacts to US national security, alliance readiness, and deterrence vis-à-vis Russia. (There are currently approximately 85,000 US troops stationed in Europe.) Furthermore, the bill requires that the military leader of United States’ European Command remain in the position of Supreme Allied Commander Europe (SACEUR), a key role in NATO that commands and controls NATO forces in the alliance.

The NDAA also includes protection and support for the United States’ most exposed allies. After the Pentagon expressed a desire to cut support for the Baltic States, Congress added an amendment requiring the secretary of defense and the commander of EUCOM to establish and implement a Baltic Security Initiative (BSI) for the “purpose of deepening security cooperation with the military forces of the Baltic countries”. While the bill also requires Estonia, Latvia, and Lithuania to match the funds the United States invests in the initiative, it entrenches support for vulnerable NATO allies during a moment of uncertainty for Europe. Additionally, the NDAA provides for regional economic and security support in the western Balkans and allows the Pentagon to continue joint construction projects for defense installations in Poland that are using Polish financial contributions.

While these requirements do not guarantee that the administration will be unable to withdraw from Europe over time, they do create political and legal conditions that would ensure that European leaders are not caught by surprise should the administration move in this direction.

Congress remains concerned about the threat from Russia

In contrast to the 2025 National Security Strategy, which takes a far more conciliatory stance toward Russia than previous administrations, the NDAA repeatedly identifies the Russian Federation as a threat to regional stability and US security. Furthermore, it identifies the growing alliance between the People’s Republic of China and Russia as a particularly challenging geopolitical development. It maintains prohibitions on the purchase and use of Russian energy, prohibits industrial-base funds from being used in Russia, extends the freeze on Russian assets over the war in Ukraine, and identifies Russia as a malign influence in the Arctic region.

Most significantly, the 2026 NDAA requires that the Pentagon now submit an annual report that must address, among other items: Russian military strategy and force posture in critical regions; the threat of Russian aggression toward NATO allies and Ukraine; conventional and nuclear modernization and proliferation programs, and Russian relations with other adversarial countries including but not limited to China, North Korea, and Iran.

As a result, Europeans should see the NDAA as a strong signal that Congress prioritizes Russia as a security threat. However, European leaders should expect to encounter divergence among different parts of the US government in their assessment of the Russian threat.

Security assistance to Ukraine will not disappear

Congress has also authorized additional support for Ukraine—albeit to a less significant degree than in previous years during Russia’s war. Considering the administration’s urgent push toward a deal with Russia and its pressure on Ukraine, this difference between the NSS and the NDAA is notable. The proposed legislation calls for the Pentagon to include $400 million in both FY2026 and FY2027 for the Ukraine Security Assistance Initiative (USAI), which is money that Ukraine can use to buy arms from the US defense industry. This is considerably different from the levels of military support for Ukraine provided in previous years, especially considering the roughly $70 billion in Congressionally approved support to Ukraine since the full-scale invasion. Justice for and reporting on Ukrainian children abducted by Russia, a key galvanizing issue across Congress, have also been included in the bill.

While these measures may not match the scale of the threat Russia presents to Ukraine and the transatlantic alliance, having the president’s signature on these laws will keep the United States involved on these sensitive issues as it navigates its position on Ukraine. The NDAA also shows which Ukraine-related issues matter most for Congress at a broad political level: a minimum of defense support and justice for tens of thousands of kidnapped Ukrainian children.

Conclusion

The passage of the 2026 NDAA this week has revealed a measured distance between Congress and the White House on European security and defense issues. Europeans should note that Congress remains a stalwart pro-NATO body even as it asks Europe to shoulder more responsibility for its own defense. Yet, even its most pro-European and pro-NATO passages are unlikely to dissuade administration efforts to disengage from the continent. Congress has attempted to limit the degree to which Europe will be surprised and significantly harmed by changes in US priorities and posture, despite the fact that the NDAA cannot fundamentally alter the changing strategic priorities articulated by the US president and his cabinet.

The differences between Congress and the White House on European security issues have increased the pressure on Europeans to determine how quickly and forcefully Europe must shift its defense posture in response to changing US priorities.

European leaders may certainly pursue mutual cooperation with the United States on issues related to NATO, Baltic security, Russian aggression, and assistance to Ukraine, but they will be met with varying degrees of enthusiasm on the US side. As the Pentagon releases additional strategic documents, including the National Defense Strategy (NDS), Europe will gain further clarity about the true urgency of the moment. European leaders should therefore look to the detailed NDS as the bellwether of the administration’s plans to implement its defense priorities and adjust to concerns raised by Congress in the NDAA. Changes to US posture and engagement with Europe are undoubtedly coming, but the NDAA offers some indication that the United States and its coequal branches of government have not finalized this debate among themselves.

The views expressed herein are those solely of the author(s). GMF as an institution does not take positions.