Turkey clears Sweden for NATO. Hungary is left holding the door.

The two decisions arrived in sequence. On 25 January, Recep Tayyip Erdoğan completed Türkiye's ratification of Sweden's NATO accession protocol. On 26 January, the Biden administration notified Congress of a possible $23 billion sale of F-16 aircraft and modernisation equipment to Türkiye.

For Stockholm, the first decision ended more than a year and a half of negotiations with Ankara. For Erdoğan, the second offered progress on a defence purchase long entangled with his relationship with Washington. Neither decision meant that Sweden had joined NATO by the end of the month.

Hungary remained the sole ally yet to ratify. Viktor Orbán's government says it supports Swedish membership, while the vote needed to turn that support into an accomplished act remains outstanding. With Ankara's file closed, Budapest can no longer share the attention with a larger holdout.

The change is significant for the alliance's northern defence plans. It is also a lesson in how accession works: an applicant can be broadly welcomed, militarily useful and politically close to most members, yet still depend on negotiations extending far beyond its own qualifications.

A signature after twenty months of argument

Türkiye's parliament approved Sweden's protocol on 23 January. Erdoğan's signature and publication of the relevant decisions followed on 25 January, completing the domestic ratification process. The steps matter because a president's statement of support alone was never the final legal act.

Sweden and Finland applied together in May 2022 after Russia's full-scale invasion of Ukraine transformed their security debate. Finland became a member in April 2023. Sweden's application remained caught in Ankara's objections, even as its neighbour crossed the threshold.

Türkiye argued that Sweden had been too permissive towards organisations and individuals it regards as security threats. The dispute included the Kurdistan Workers' Party, or PKK, which is designated a terrorist organisation by Türkiye, the EU and the United States. Ankara's wider requests and definitions did not always coincide with Swedish law.

Stockholm introduced legal changes concerning participation in terrorist organisations and expanded cooperation. The legislation gave authorities additional tools, but its application still depended on evidence and judicial procedures. A government commitment to strengthen enforcement is different from a promise that every person named by a foreign government will be prosecuted or extradited.

That legal boundary was a recurring difficulty in the negotiations. Swedish ministers could change policy and seek legislative amendments. They could not lawfully instruct an independent court to produce a particular result simply to meet a diplomatic timetable.

Public demonstrations added another source of friction, particularly Quran-burning incidents and protests directed at Erdoğan. Swedish officials could condemn offensive actions while explaining that domestic protections for expression limited the government's ability to prohibit them. Ankara judged the same incidents through security, religious and political concerns of its own.

These episodes gave people outside the formal negotiation an ability to disrupt it. A provocative act could trigger a new diplomatic confrontation even when officials believed the technical work was advancing. That made the timetable vulnerable to developments neither government fully controlled.

The July 2023 understanding at Vilnius moved the process forward, but ratification still took months. The delay is a reminder that summit language promising parliamentary action should be followed through to the recorded vote and legal completion. For Sweden, January finally supplied those completed steps on the Turkish side.

Erdoğan can now say that his pressure produced policy changes and a stronger security relationship. Sweden can say it met legitimate cooperation needs while retaining its legal order. Both accounts will be tested by how the relationship functions after accession is no longer available as an immediate bargaining instrument.

The aircraft deal has its own institutions

The US notification concerns 40 new F-16 aircraft and equipment to modernise 79 existing Turkish aircraft, together with associated systems and support. The published estimate is an upper package value, not evidence that every item has already been contracted or delivered.

Washington also notified a possible F-35 sale to Greece. The parallel announcement reflects a regional defence relationship in which decisions concerning one ally are closely watched by another. It should not be described as a transfer of aircraft that has already changed the military balance in the Aegean.

The F-16 issue had been publicly linked to Sweden's accession in the political negotiations. The January sequence makes that connection visible. It does not eliminate the separate US legal process governing arms sales, or mean that Erdoğan and Biden alone could complete every stage.

Congressional scrutiny is an essential part of that process. Members can raise concerns about the recipient's conduct, regional security and the use of equipment. Administration support is therefore consequential without being identical to a finished commercial transaction.

The distinction also matters for Türkiye's air force. Modernisation requires training, maintenance arrangements, infrastructure and a delivery schedule. Announcing a large purchase can reassure planners about a future fleet, but it does not solve today's readiness requirements overnight.

For Biden, the broader argument is that a stronger and more coherent NATO serves US interests, including in northern Europe. For critics of the arrangement, the concern is the precedent: an ally may learn that delaying a shared objective is a way to secure concessions on another file.

Both considerations can be true. A bargain may improve the alliance's immediate strategic position while encouraging costly behaviour in future negotiations. The relevant question is whether the value gained now is accompanied by enough clarity about future expectations to limit that incentive.

Türkiye's importance gives the negotiation weight beyond the Swedish application. Its armed forces, geography and role around the Black Sea make a sustained breakdown with Washington costly for both sides. That does not make every Turkish demand persuasive; it explains why the relationship cannot be reduced to one disputed vote.

Nor does the aircraft announcement settle all bilateral disagreements. It advances one defence file in a relationship containing differences over regional conflicts, military partnerships and domestic rights. Describing January as a complete reconciliation would overstate what either government has demonstrated.

For European capitals, the lesson is practical. When a European security objective depends on a decision in the US Congress, diplomacy has to account for that institution early. Treating the White House as the sole decision-maker can leave a negotiated package waiting at a second door.

Budapest loses its cover

Orbán spoke in favour of Swedish membership as Türkiye's process reached its conclusion. Hungary's government has nevertheless attributed delay to concerns among its parliamentarians, including resentment over Swedish criticism of the state of Hungarian democracy.

The distinction between government support and parliamentary hesitation is formally possible. Politically, it invites scrutiny because Orbán's governing camp controls a strong majority. Other allies are entitled to ask what specific issue remains unresolved and what step would allow the vote to proceed.

An invitation for Prime Minister Ulf Kristersson to visit Budapest adds another diplomatic stage. Kristersson responded positively to further dialogue, while the governments also had an opportunity to meet at the coming European Council. Agreement to talk is useful, but it is not ratification.

Hungary's objections differ from Türkiye's. There is no equivalent publicly defined package of Swedish counter-terrorism legislation whose completion would plainly settle the Hungarian file. That makes it harder to assess progress against a stable set of requirements.

A dispute about respectful relations can be politically important without being a clear accession criterion. If criticism of a member government's domestic practices becomes a reason to hold up another democracy's application, prospective members receive a troubling message about the cost of speaking openly inside an alliance.

The pressure on Budapest will now be concentrated. Before Türkiye completed its process, Hungary could remain one of two unresolved cases. As the only remaining ally withholding ratification, it becomes directly responsible for the continued delay in completing enlargement.

That does not guarantee an immediate vote. Isolation can encourage compromise, but it can also increase the political value a leader places on demonstrating independence from outside pressure. Predicting a date requires evidence from the parliamentary timetable, not simply an assumption that the diplomatic argument has become embarrassing.

NATO's secretary general can press the case, coordinate allies and emphasise Sweden's contribution. He cannot cast Hungary's parliamentary votes. The alliance's consensus rule is a distribution of national authority as well as a statement of unity.

Swedish diplomacy therefore has to combine patience with a clear account of what has already been done. An endlessly expanding negotiation would make it difficult for any government to explain the process at home. A bounded discussion of remaining concerns could instead give Budapest a route to approval without pretending the delay has been costless.

What Sweden changes on the map

Sweden's military value is not confined to the symbolic addition of another flag. Its territory connects Norway and Finland with the Baltic Sea, and its forces bring established air, maritime and land capabilities. Membership would allow those assets to be incorporated into allied defence arrangements with greater political certainty.

Gotland's position is particularly relevant to activity in the Baltic. Geography can support surveillance and the movement of forces, but an island does not defend itself because it appears in a strategic diagram. Units, supplies, protected infrastructure and the ability to reinforce them determine the practical advantage.

Sweden has worked with NATO for years, including through exercises and operational cooperation. Membership would deepen that relationship rather than create military familiarity from nothing. It would also change obligations: Sweden would help plan the defence of allies and expect their participation in its own defence.

That mutuality is important to the domestic debate. Accession is not simply the purchase of protection from outside. Swedish governments would take part in decisions about risks elsewhere in the alliance and would need to prepare forces for commitments beyond national territory.

The defence cooperation agreement signed with the United States in December provides another channel for closer military arrangements. At the end of January, its signature and the domestic work required to bring it into force must be distinguished. It does not independently make Sweden a NATO member or replace the accession process.

Bilateral agreements and NATO membership can complement each other. The former can set practical conditions for access and cooperation; the latter establishes the wider political and collective-defence framework. Confusing the two risks overstating what a particular document obliges another government to do.

For Finland, Sweden's completion would make regional planning less awkward. The countries have developed close defence cooperation, and their different membership status creates a political boundary inside a tightly connected geography. Removing it would simplify some planning assumptions without eliminating operational challenges.

The Baltic should not be described as secured by enlargement alone. Russia retains capabilities in the region, and critical infrastructure remains exposed to a range of threats. Allied presence and coordination can improve deterrence while still requiring continued investment and careful assessment of incidents.

The waiting period is a policy choice too

Sweden is not without partners while it waits. Existing cooperation and political assurances provide important support. Their existence does not mean delay is irrelevant: governments and military planners still need clarity about the treaty framework under which they would act.

The longer an accession process remains unresolved after an invitation, the more it encourages parallel arrangements to manage uncertainty. Those arrangements can be useful, but they add complexity and can leave different assumptions about who is responsible for what in a crisis.

Completion would move the debate from whether Sweden can enter to how it contributes. That includes force readiness, defence spending, civil preparedness and the infrastructure needed to receive assistance. These tasks require sustained work even when the political ceremony is eventually over.

January has removed the largest prolonged obstacle. Ankara's ratification is complete, Washington's aircraft notification has been made and Budapest's outstanding vote is now the central issue. These are measurable changes, more precise than another claim that membership is within reach.

For Kristersson, the next achievement must be less ambiguous than a successful meeting. It is the remaining ratification and the completion of accession under the treaty process. Sweden has spent months demonstrating that it can meet the alliance's expectations. The final question now concerns whether the alliance's last holdout is ready to complete its own part.