U.S. Congress Passes Defence Bill Locking American Troops Into Europe, Backing Ukraine, Limiting Trump

On 17 December 2025, The United States Congress has passed a sweeping defence bill that entrenches America’s military commitment to Europe and guarantees continued support for Ukraine, delivering one of the clearest institutional rebukes yet to President Donald Trump’s approach to foreign and security policy.

The legislation, the National Defense Authorization Act (NDAA) for fiscal year 2026, was approved by large bipartisan majorities in both chambers, reflecting deep concern among lawmakers about the direction of U.S. strategy under the Trump administration. The bill now awaits the president’s signature, which is widely expected despite its direct constraints on executive power.

A Bill That Freezes the Status Quo in Europe

At the heart of the NDAA are provisions designed to prevent a rapid or unilateral drawdown of U.S. forces stationed in Europe. The law requires that American troop levels on the continent cannot fall below current thresholds for any sustained period without detailed justification to Congress and formal consultation with NATO allies.

In practical terms, the bill locks tens of thousands of U.S. troops into Europe, reinforcing NATO’s eastern flank at a time of continued tension with Russia. It also authorises funding to sustain U.S. military infrastructure and rotational deployments in Eastern Europe and the Baltic states, signalling a long-term commitment rather than temporary reassurance.

For European governments unsettled by repeated suggestions from President Trump that the U.S. could scale back its NATO role, the vote offers a measure of stability. It makes clear that, regardless of White House rhetoric, the American legislature remains invested in the post-war security architecture of Europe.

Ukraine Funding Extended

The bill also guarantees security assistance for Ukraine through at least the next two fiscal years. While the precise allocation will be finalised through appropriations, Congress has committed hundreds of millions of dollars for training, equipment, and logistical support, maintaining a policy line that has enjoyed bipartisan backing since Russia’s full-scale invasion.

This provision stands in contrast to the Trump administration’s sceptical stance on long-term aid to Kyiv and reflects congressional concern that wavering U.S. support could embolden Moscow or fracture Western unity.

Congress Moves to Contain the President

Beyond its military substance, the NDAA is politically significant for what it says about power in Washington. Lawmakers from both parties have framed the bill as a necessary guardrail against abrupt strategic shifts driven by presidential preference rather than alliance consensus.

Trump’s own national security rhetoric has repeatedly criticised the European Union, questioned NATO’s value, and hinted at a more transactional relationship with Russia. By embedding troop commitments and alliance obligations into statute, Congress is asserting that dismantling the post-1945 security order is not solely a presidential decision.

The result is a rare moment of institutional confrontation: a president advancing a disruptive foreign-policy vision, and a legislature actively working to constrain it.

Good News for Europe, With Caveats

For Europe, the vote is broadly reassuring. It reduces the risk of sudden U.S. military withdrawal and confirms that the American security establishment — not just the executive branch — remains committed to deterrence and collective defence.

But analysts caution that containment in one domain often leads to pressure in others. While troop levels may now be harder to cut, a Trump administration constrained on security could intensify leverage elsewhere, particularly through trade policy, technology regulation, food standards, and investment threats.

In other words, the tanks may stay, but coercion could shift to economic and regulatory fronts.

Why Britain Is Exposed

This dynamic carries particular implications for the United Kingdom. Outside the European Union, Britain lacks the collective economic weight and regulatory shield that EU membership provides when facing U.S. pressure.

Where the EU absorbs pressure collectively, with scale and leverage, the UK negotiates bilaterally. That leaves Britain more vulnerable to shifts in U.S. policy, especially if Washington uses trade or market access as leverage while military cooperation remains formally intact.

The congressional vote also undercuts the logic behind the idea that managing Trump through personal diplomacy alone can secure British interests. The bill demonstrates that Washington’s centre of gravity on security lies not in appeasement, but in institutional containment.

A Divided United States, A Clear Signal Abroad

The passage of the NDAA lays bare an internal divide within the United States. The president is pushing toward a narrower, more transactional conception of American power. Congress, supported by the defence and security establishment, is insisting on continuity, alliances, and restraint.

For allies, the message is mixed but unmistakable. The U.S. remains committed to Europe — but not because of presidential goodwill. That commitment now rests on legislative force.

As the bill moves toward enactment, it will shape transatlantic relations for years to come, reinforcing NATO in the short term while highlighting the deeper uncertainty created by a United States increasingly split over its role in the world.