Two things happened within days of each other this spring, and almost nobody read them as a single story. On 26 March, Senators Ted Budd and Joni Ernst introduced the Abraham Accords Defense Cooperation Act of 2026, a bill instructing the Pentagon to stand up a funded initiative for military cooperation across a bloc of states stretching from Morocco to Kazakhstan. Four days later, Spain shut its airspace to American aircraft tied to operations against Iran, having already barred United States (US) use of the Rota and Morón bases. One event was a legislative proposal in Washington. The other was a North Atlantic Treaty Organisation (NATO) member, for the first time since the Cold War, telling the United States no.
Read separately, these look like unrelated news items, a defence procurement story and a diplomatic disagreement. Read together, they describe something more consequential: Washington is building a new security architecture in the Middle East at precisely the moment its existing one in Europe is showing strains it cannot easily resolve.
What the bill actually does
Strip away the commentary and S.4219 is a fairly narrow piece of legislation. It directs the Secretary of Defense to establish a “United States-Abraham Accords Defense Cooperation Initiative”, covering countries that signed the original 2020 accords, the United Arab Emirates (UAE), Bahrain, Morocco and Sudan, plus any state that has pursued normalisation with Israel since. The bill requires the Secretary to prioritise deterring Iranian aggression while enhancing regional planning and cooperation, including counter-unmanned aerial system (UAS) capabilities, ground-based air defence, special operations force development, and joint exercises. It also requires a strategy report to the Senate Armed Services Committee, alongside a budget request. Both senators sit on that committee, and they are hoping to fold the initiative into this year’s National Defense Authorization Act (NDAA), which, if it happens, turns a standalone bill into permanent budgetary architecture almost overnight.
None of this is subtle about its target. As Ernst’s office put it, the Accords delivered a united front against Iran, building on her earlier DEFEND Act. Budd’s framing was equally direct: Gulf partners such as Bahrain and the UAE remain exposed to Iranian missile and drone threats, and deeper coordination could encourage further Arab states to normalise relations with Israel.
A commentary in the Times of Israel described the bill as the blueprint for a regional “NATO-lite” running from the Atlantic to Central Asia. Whatever one makes of that label, the geographic sweep is real. What matters for policy purposes is not the label, however, but the funding stream, the NDAA pathway, and the fact that this initiative requires none of the consensus-building that NATO does. The Secretary of Defense executes; the partners receive. That structural difference deserves more attention than it has received.
Spain says no
Set that against what happened in Madrid.
Spain’s position emerged in stages. First, the Foreign Ministry indicated that the Rota and Morón bases were not being used for operations against Iran; then Defence Minister Margarita Robles confirmed the bases were formally off-limits. By 30 March, Robles extended the prohibition to Spanish airspace itself, telling reporters that neither the bases nor Spanish airspace were authorised for any action related to the war in Iran, which she described as profoundly illegal and unjust.
This was not a minor logistical inconvenience. Flight-tracking data showed fifteen US aircraft relocating out of the Spanish bases, with several landing at Ramstein in Germany. Rota and Morón have functioned for decades as key hubs for American operations into Europe, Africa and the Middle East, and the airspace closure cut off a second logistical pathway entirely. President Trump responded by threatening to cut trade with Madrid.
How unusual is this, historically? Coverage of the episode pointed to two precedents: France and Italy blocking US airspace for the 1986 raid on Libya, and Turkey refusing to let US troops transit for the 2003 invasion of Iraq, though Ankara still permitted overflights. Spain’s move goes further than either. It is not a transit refusal for ground troops, and it is not a one-off wartime exception. It is a blanket policy covering both bases and airspace, sustained over weeks, against a NATO ally currently engaged in active combat operations.
Spain was not alone, either. Other allies hedged in varying degrees: Britain initially withheld base access before authorising it under collective self-defence, while France and Germany signalled willingness to follow suit. Switzerland approved only a minority of US airspace requests in late March, citing its neutrality laws, and Italy denied landing rights at a base in Sicily. Spain sits at the extreme end of a spectrum, not in isolation.
The asymmetry nobody is naming
Here is the part that should concern anyone thinking about transatlantic defence planning rather than just this week’s headlines.
The Abraham Accords Defense Cooperation Act creates a funded, institutionalised cooperation framework with states that carry no treaty obligation to the United States. The UAE, Bahrain and Morocco are bound by nothing resembling Article 5 of the North Atlantic Treaty. Their participation is transactional, bilateral, and revocable at will, precisely the opposite of what NATO membership is meant to guarantee. Yet this is the relationship Washington has chosen to formalise with a dedicated budget line and a congressional reporting requirement.
Meanwhile, a treaty ally, a NATO member, with all the Article 5 guarantees that implies, closed its airspace to US combat operations and faced little beyond a tariff threat issued on social media.
This asymmetry is unlikely to be an oversight. It looks more like a preference, and arguably a rational one given the actors involved. Gulf partners can deliver what NATO increasingly struggles to: speed, discretion, and freedom from the kind of domestic political constraint that took Rota and Morón off the table. Spain’s governing coalition answers to a domestic electorate where opposition to the war in Gaza runs deep; the governments of the UAE and Bahrain face no equivalent constraint. From Washington’s perspective, the incentive to build a parallel framework that delivers consistent cooperation is clear, even if the framework sits outside the alliance that has anchored US strategy in Europe since 1949.
Where neoclassical realism helps
This is where international relations theory does useful explanatory work rather than serving as decoration. Structural realism alone struggles to account for Spain’s behaviour: systemically, Madrid gains little and risks friction with its principal security guarantor by defying Washington. The variable that matters here is domestic, coalition composition, public opinion on Gaza, and a prime minister who has staked considerable political capital on positioning Spain as one of Europe’s most vocal critics of the war. Neoclassical realism’s central proposition is that systemic pressures are refracted through domestic politics before they produce state behaviour, and Spain’s position in March 2026 illustrates that proposition clearly.
The Gulf states do not face an equivalent refraction. Their governance structures mean that elite calculations about regional threat perception translate into policy with comparatively little domestic friction. When Washington compares the responsiveness of its Gulf partners with that of a European ally, it is not making a like-for-like comparison: one side of the comparison involves a short, direct link between systemic incentive and state action, while the other runs through an unpredictable domestic political process.
The risk is that policymakers come to treat this asymmetry as a feature rather than a symptom. If Gulf partners are easier to work with, institutional logic will continue directing resources, attention and funded initiatives toward them, reinforcing the very dynamic that contributed to Spain’s position in the first place. It is a feedback loop, and at present it runs in one direction.
Implications for the eastern flank
For states on NATO’s eastern border, the Spanish episode and the Abraham Accords Defense Cooperation Act together raise a question with little direct connection to Iran; if Washington can build a faster, better-funded, consensus-free security architecture with non-treaty partners in one theatre, what is the long-term incentive to maintain the slower, consensus-bound architecture in another?
Eastern flank states have long argued that consensus-based decision-making, however cumbersome, is the price of collective legitimacy, and that this legitimacy is itself a deterrent, since it signals that the alliance holds together under pressure. But legitimacy only deters if an adversary believes the alliance functions as a unit when it matters. Spain’s position, however justified Madrid considers it on its own terms, is a data point that Moscow is likely to read carefully, not because it concerns the Middle East, but because it demonstrates that NATO membership does not guarantee operational cooperation even from a major member during an active conflict involving the alliance’s principal security guarantor.
Baltic and Central European governments do not need the United States to abandon NATO to feel the effects of this dynamic. They need only observe where the institutional energy, funding mechanisms and NDAA line items are directed. At present, these point toward Rabat, Manama and Abu Dhabi, not because those capitals matter more than European allies, but because cooperation with them is, for now, less complicated.
An unmade choice
Nothing in S.4219 forces a reckoning with NATO’s internal divisions. It does not need to. The bill can pass, the initiative can stand up, the NDAA line item can be funded, and none of it needs to reference Spain, Article 5, or intra-alliance burden-sharing. The fracture requires no formal trigger. It only requires Washington to continue finding it easier to build new architecture than to repair the existing one.
There remains a version of events in which NATO absorbs this divergence, where allies agree, even tacitly, that out-of-area operations do not require alliance-wide consensus, and where disagreement over Iran does not bleed into core deterrence commitments closer to home. That outcome is not impossible. But it requires someone to manage the divergence deliberately, rather than allow it to accumulate as a by-product of decisions taken for entirely separate reasons. So far, that management has not been visible. The Abraham Accords Defense Cooperation Act was not written with NATO cohesion in mind at all, and that, more than anything in its text, is the point worth noting.
