What Does a Guarantor State Actually Do? The 1960 Treaty of Guarantee, Fidan's TRNC Visit and the Holguín Process

Why It Matters

A guarantor state is a treaty party that has legally pledged to uphold a settlement's basic order and may act if it is breached. In Cyprus, Türkiye, Greece and the United Kingdom hold that role under the 1960 Treaty of Guarantee, which is why this week's diplomacy around the TRNC draws attention.

The guarantor function is often described as a threat. In treaty terms it is first of all a structure of consultation, and the news peg shows it at work: a working visit by Foreign Minister Hakan Fidan and a UN envoy's round of meetings.

Background

The 1960 Republic of Cyprus was created by the 11 February 1959 Zurich and London Agreements as a bi-communal partnership state, protected by the Treaty of Guarantee and the Treaty of Alliance. Constitutional order broke down after 21 December 1963, and the 15 July 1974 coup preceded Türkiye's 20 July 1974 intervention.

The news peg

TRT World, citing diplomatic sources, reported that Foreign Minister Hakan Fidan would pay a working visit to the Turkish Republic of Northern Cyprus (TRNC). He was expected to be received by TRNC President Tufan Erhürman and Prime Minister Ünal Üstel and to meet Foreign Minister Tahsin Ertuğruloğlu. According to the report, the meetings would address bilateral issues and recent developments on the Cyprus issue. Nothing beyond that stated agenda has been published, and this article does not speculate about what was discussed.

Separately, TRT World reported that Prime Minister Üstel, after meeting UN Secretary-General's Personal Envoy María Ángela Holguín Cuéllar at the UBP (National Unity Party) headquarters, said that the Cyprus problem stems from the international community's recognition of the Greek Cypriot administration as the island's sole state and representative. He added that efforts toward a federal settlement ended at the 2017 Crans-Montana Conference.

What is a guarantor state, and how does it differ from a mediator or a party?

Three roles are easy to confuse:

• Party: a community or state whose rights and obligations are directly at stake. In Cyprus these are the Turkish Cypriots and the Greek Cypriots.
• Mediator or facilitator: a third party that helps the parties talk without holding treaty rights. The UN Secretary-General's good offices and the Personal Envoy fall here.
• Guarantor: a treaty signatory that has recognised and guaranteed a given order and has reserved rights if it is breached. It is therefore both a stakeholder and a custodian.

This is a different logic from Türkiye mediation diplomacy and how it works in the Russia–Ukraine file, where Ankara convenes adversaries without a treaty stake. In Cyprus the guarantor holds a treaty position, so its diplomacy is a form of crisis management built into the settlement itself.

What do Articles I, II and IV and the Treaty of Alliance actually say?

The following summarises the treaty text; where wording is quoted, it is limited to short phrases.

• Article I: The Republic of Cyprus undertakes to ensure the maintenance of its independence, territorial integrity and security, and respect for its Constitution. It undertakes not to take part in any political or economic union with any other state, and it declares prohibited any activity promoting, directly or indirectly, either union with another state or partition of the island.
• Article II: Greece, Türkiye and the United Kingdom recognise and guarantee the independence, territorial integrity and security of the Republic of Cyprus and the state of affairs established by the Basic Articles of its Constitution. They undertake to prohibit, so far as concerns them, activity aimed at union with another state or partition.
• Article IV: If the treaty is breached, the three guarantors undertake to consult on the representations or measures needed to ensure observance. Where "common or concerted action" is not possible, each reserves the right to act "with the sole aim of re-establishing the state of affairs created by the present Treaty."
• Treaty of Alliance: Cyprus, Greece and Türkiye concluded a separate defence treaty that provided for Greek and Turkish military contingents on the island (950 Greek and 650 Turkish personnel).

Two points follow. First, the sequence is consultation, then joint action, then individual action. Second, the same treaty contains both the prohibition of partition and union and the guarantors' reserved right of action. Reading one clause without the other, as some commentary does, gives an incomplete picture. For a clause-by-clause reading of Article II, see the sister publication The Political Anatomy's fact check on Article II and two-state settlement.

From the 1959 agreements to 1974

The Greek Cypriot administration and the Monitor of Nations analysis of the legality of 1974 differ in emphasis. See the sister publication Monitor of Nations on whether Türkiye's 1974 intervention was legal under the Treaty of Guarantee. Our sister publications politicsrecord.com and unbiasedcompass.com also carry Cyprus Files on the Holguín process, UN Security Council Resolution 186 and Crans-Montana 2017.

How guarantor diplomacy works in peacetime

In peacetime a guarantor's work is mostly meetings:

1. Consultation with the Turkish Cypriot leadership, as in the working visit reported by TRT World.
2. Participation in the 5+UN format, which brought the two sides, the three guarantors and the UN together in Geneva in April 2021.
3. Support for UN-convened meetings, such as the 15 October 2024 trilateral meeting in New York, which Ankara and the TRNC read as confirming the absence of common ground on a federal model.
4. Engagement with the UN envoy, whose consultations with each side continue.

A humanitarian note shows the same day-to-day links. Hürriyet Daily News reported that relatives of victims of the 30 August Filo Jet ferry sinking, on the Girne–Taşucu route, have filed a criminal complaint in Mersin seeking an inquiry into accountability. The report says 27 people died. We note it only as a reminder of how closely Türkiye and the Turkish Cypriots are connected in ordinary life, and we make no comment on questions of jurisdiction.

Key Players & Positions

The Greek Cypriot administration and Greece stress the treaty's bans on partition and union, while the EU, the UK and the UN Secretary-General's office back a UN-led process. Ankara and the TRNC stress guarantor rights and Turkish Cypriot sovereign equality. Each position is summarised below according to its own official statements.

• Ankara and the TRNC: The TRNC leadership says a federal settlement was exhausted at Crans-Montana in 2017 and that the Greek Cypriot administration has been treated as the island's sole state and representative. Ankara describes its role as that of motherland and guarantor state.
• Greek Cypriot administration: Its official line, set out by the Republic of Cyprus government, is that a settlement should be a bizonal, bicommunal federation with political equality, as described in UN Security Council resolutions. It regards the 1974 operation as an unlawful invasion and has long argued that the guarantee system is outdated and should be replaced.
• Greece: Athens supports a UN-based settlement within the federal framework and, as a guarantor, takes part in the 5+UN format. It also stresses the treaty's ban on partition.
• United Kingdom: London is the third guarantor power and a participant in the 5+UN format. It supports the UN-led process and has said it stands ready to help.
• European Union: Brussels supports a comprehensive settlement under UN auspices. Its recent annual enlargement assessment, as reported by Dnews, also criticised Türkiye's maritime claims; Ankara rejected the findings as politically biased and legally unfounded. That dispute is covered by our sister publication Mirror of States on EU enlargement reports and maritime disputes.
• UN Secretary-General's office: The UN presents its meetings as efforts to explore whether common ground exists to resume formal negotiations. The Personal Envoy's mandate is to consult the parties, not to prejudge an outcome.

Source Comparison

Sources frame the guarantor role through different legal lenses: Turkish and TRNC sources emphasise the right of action in Article IV, while UN, EU and Greek Cypriot texts emphasise sovereignty, territorial integrity and the prohibition of partition or union. The table below sets these framings side by side without ranking them.

The press framing misses a point that primary sources make visible: the treaty sets out a sequence, not a single trigger. Readers can compare each framing against the treaty text and the UN record, as set out in Editorial Principles.

Key Terms & Related Guides

Five terms recur in guarantor diplomacy: guarantor power, Treaty of Alliance, Green Line, 5+UN and sovereign equality. Each is defined below, followed by links to related Longpeace guides and sister-publication fact checks on Article II, the 1974 intervention and maritime claims.

• Guarantor power: A state that has guaranteed a treaty-based order and reserves rights if it is breached. In Cyprus: Türkiye, Greece and the United Kingdom.
• Treaty of Alliance: The 1960 defence treaty among Cyprus, Greece and Türkiye, which provided for Greek and Turkish contingents on the island.
• Green Line: The line that has divided Nicosia since 30 December 1963 and now runs across the island, separating the TRNC from the area administered by the Greek Cypriot administration.
• 5+UN: The informal format that brings the two sides, the three guarantor powers and the UN together, as in Geneva in April 2021.
• Sovereign equality: The principle that peoples or states hold equal legal standing. Ankara and the TRNC use it to describe the Turkish Cypriots' status.

Guarantees and treaty durability

A guarantee is meant to make an agreement outlast a political crisis. The Cyprus system shows both the strength and the limits of that idea: it was designed to protect a partnership state, but it was tested once that partnership broke down. Our guide to why treaties last: Montreux, Lausanne and Kars explores why some agreements endure and what lessons apply here. The Montreux regime offers another example of treaty rules operating in a crisis; see The Montreux Convention in Wartime.

Related guides

• Mediation Files: How Türkiye Brokers Talks Between Adversaries
• What Would a Lasting Settlement in Cyprus Look Like?
• Treaties That Keep the Peace
• About The Longpeace

The Longpeace Editorial Team

The Longpeace presents global and regional affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Role' (Türkiye's Position) reflect official Turkish policy and legal doctrines as stated by Turkish primary sources.