Cyprus and the 1960 Treaty of Guarantee: What It Says and Why It Matters

Why It Matters

The 1960 Treaty of Guarantee is the legal instrument by which Greece, Türkiye and the United Kingdom guaranteed the independence, territorial integrity and security of the Republic of Cyprus, and prohibited both union with another state and partition. Its Article IV, which allows a guarantor to act if joint action proves impossible, was invoked by Türkiye in July 1974, and it is still the most contested legal question in every round of UN-led talks. Whether the treaty is treated as obsolete or indispensable determines how security, troops and the shape of any settlement are negotiated.

Quick answers

• What does the treaty allow? It lets each guarantor consult with the others when the treaty is breached and, if joint action is impossible, take action “with the sole aim” of restoring the treaty-created state of affairs. Its scope, and whether it covers military force, is disputed.
• Is it still valid? It has not been terminated by agreement, annulled by a court or replaced by a new treaty. Its continued legitimacy is contested: Greek Cypriots, Greece and the EU institutions favour ending the guarantee system, while Ankara says it remains in force.
• Why are there two sides? The 1960 power-sharing republic broke down in 1963, and the 1974 coup and intervention split the island de facto along the UN-patrolled buffer zone. Two communities now have different views of that history and of the future.

Background

The 1959–1960 settlement

The settlement was negotiated after the 1955–59 period of violence on the British-ruled island, which involved the Greek Cypriot EOKA campaign for enosis (union with Greece) and Turkish Cypriot demands for taksim (partition). The Zurich agreement between Greece and Türkiye (11 February 1959) and the London agreements (19 February 1959), endorsed by the British government and by the Greek Cypriot and Turkish Cypriot community leaders, produced an independent state rather than either option. Cyprus became independent on 16 August 1960 under a package of instruments:

Instrument	Parties	Main content
Constitution (Basic Articles)	Two communities	Greek Cypriot President and Turkish Cypriot Vice-President, each with veto powers over key matters; a 70:30 House seat ratio; separate communal chambers; set quotas in the civil service and security forces
Treaty of Guarantee	Cyprus, Greece, Türkiye, UK	Guarantees independence, territorial integrity and the constitutional order; bans enosis and partition; Article IV on action by guarantors
Treaty of Alliance	Cyprus, Greece, Türkiye	Greek and Turkish military contingents stationed on the island (950 and 650 personnel respectively)
Treaty of Establishment	Cyprus, UK	The UK retains the Sovereign Base Areas of Akrotiri and Dhekelia

At independence, Greek Cypriots made up roughly 77 percent of the population and Turkish Cypriots roughly 18 percent, with Armenians, Maronites and Latins making up the remainder.

What the Treaty of Guarantee says

The treaty is short. In plain terms:

• Article I: Cyprus undertakes to maintain its independence, territorial integrity and security and to respect its constitution. It agrees not to take part in any political or economic union with any state, and it prohibits activity that would promote union with another state or partition.
• Article II: Greece, Türkiye and the United Kingdom recognise and guarantee the independence, territorial integrity and security of Cyprus and the state of affairs established by its Basic Articles. They also undertake to prohibit, as far as lies within their power, activity promoting union or partition.
• Article IV: If the treaty is breached, the three guarantors undertake to consult together on the representations or measures needed to ensure respect for it. Where common or concerted action proves impossible, each of them reserves the right to take action with the sole aim of re-establishing the state of affairs created by the treaty.

The text does not say in so many words whether “action” includes military force. Ankara reads it as including force; the Republic of Cyprus, Greece and many international lawyers read it as narrower, or as limited by the UN Charter. The treaty also contains no termination or withdrawal clause.

1963–1974: breakdown of the partnership state

The constitution proved unworkable almost at once, with disputes over taxation, municipalities and the army ratio. In November 1963 President Makarios proposed thirteen constitutional amendments, which the Turkish Cypriot leadership and Ankara rejected. Intercommunal violence began in December 1963. Greek Cypriots generally say the Turkish Cypriot leadership withdrew from government and moved into enclaves, whereas Turkish Cypriots and Ankara say they were forced out of state institutions and attacked. UN Security Council Resolution 186 (March 1964) created the UN Peacekeeping Force in Cyprus (UNFICYP) and referred to the government of Cyprus, which the Council treated as the continuing authority. Turkish Cypriots lived in enclaves under restrictions, and Ankara has since argued that the 1960 partnership ended in 1963.

1974: coup and intervention

On 15 July 1974, the National Guard, led by Greek officers backed by the military junta in Athens, overthrew Makarios and installed Nikos Sampson. On 20 July, Türkiye landed troops on the north coast and said it was acting as a guarantor under Article IV. The UN Security Council, in Resolution 353 (20 July 1974), called for a ceasefire, the withdrawal of foreign military personnel other than those present under treaty, and negotiations among Greece, Türkiye and the UK. The junta in Athens fell within days. Talks in Geneva failed, and on 14 August 1974 Türkiye launched a second phase that brought roughly a third of the island under Turkish control. Estimates suggest around 160,000 to 200,000 Greek Cypriots were displaced to the south, and tens of thousands of Turkish Cypriots later moved north. The Greek Cypriot side, the UN and the EU describe this as occupation. Ankara calls it a lawful peace operation under the treaty.

After 1974: federation talks and the TRNC

• 1975: The “Turkish Federated State of Cyprus” was proclaimed in the north.
• 1977 and 1979: High-level agreements between the leaders, Makarios and Denktaş (1977) and Kyprianou and Denktaş (1979), set the goal of a bicommunal, bizonal federation. Security Council Resolution 1251 (1999) later described a settlement with a single sovereignty, international personality and citizenship, and political equality.
• 15 November 1983: The Turkish Cypriot leadership declared the Turkish Republic of Northern Cyprus (TRNC). UN Security Council Resolution 541 (1983) called this declaration legally invalid and urged its withdrawal, and Resolution 550 (1984) reaffirmed this. Only Türkiye recognises the TRNC.
• 2004: The UN’s Annan Plan was put to separate simultaneous referendums on 24 April. Roughly 65 percent of Turkish Cypriots voted yes, and roughly 76 percent of Greek Cypriots voted no. The Republic of Cyprus joined the EU on 1 May 2004, with the application of EU law suspended in the areas where the government does not exercise effective control. The Annan Plan would have kept the Treaty of Guarantee in place.
• 2008–2017: Further rounds of leader-level talks produced convergence on some chapters, notably a 2014 joint declaration, but not on security and guarantees.

Crans-Montana, 2017 and the two-state debate

A five-party conference (the two communities, the three guarantors, with the EU as an observer) met in Geneva in January 2017 and then at Crans-Montana, Switzerland, from 28 June to 7 July 2017, convened by UN Secretary-General António Guterres. It ended without agreement. The Secretary-General’s framework covered security and guarantees, territory, property, equivalent treatment of the communities and effective participation. The sticking points were the guarantee system and the Turkish troop presence, along with questions of rotating presidency and political equality. Each side blames the other for the failure.

At an informal UN meeting in Geneva in April 2021, the Turkish side, led by Türkiye and the Turkish Cypriot leader Ersin Tatar, advocated a solution based on two states with sovereign equality and equal international status. The Greek Cypriot side, Greece, the EU and the UN reiterated their commitment to the federal framework. Turkish Cypriot politics is not uniform: Tufan Erhürman, who won the October 2025 northern presidential election, supports resuming federal talks, a change of tone that observers are still assessing.

Timeline at a glance

Date	Event
11 Feb 1959	Zurich agreement between Greece and Türkiye
16 Aug 1960	Independence; Treaties of Guarantee, Alliance and Establishment in force
Dec 1963	Constitutional crisis and intercommunal violence
Mar 1964	UNFICYP established (Resolution 186)
15 Jul 1974	Coup against Makarios
20 Jul and 14 Aug 1974	Turkish intervention, two phases
15 Nov 1983	TRNC declared; Resolution 541
24 Apr 2004	Annan Plan referendums
1 May 2004	Republic of Cyprus joins the EU
Jul 2017	Crans-Montana conference ends without agreement
Apr 2021	Informal Geneva meeting; two-state vision presented by the Turkish side

Is the treaty still valid?

No termination clause exists, no guarantor has formally denounced the treaty, and no court has annulled it. Both the 1960 Republic and the guarantors acted on it for years, and the 2004 Annan Plan assumed its continuation in modified form. The legal dispute is about its compatibility with the UN Charter. The Republic of Cyprus and Greece argue that a right of unilateral military action conflicts with Article 2(4) of the Charter, which prohibits the use of force, and that under Article 103 the Charter prevails. They add that EU membership is incompatible with a right of intervention by a non-member state. Ankara responds that the treaty predates the matters at issue, that the UN Security Council has never declared it void and that Article IV was invoked after a coup that violated the ban on union with Greece. A UK parliamentary committee report in 1976 is often cited by both sides, and is generally summarised as finding that Türkiye had a right to act under the treaty but that the scale of the later action went beyond it.

Key Players & Positions

Republic of Cyprus (Greek Cypriot leadership)

The internationally recognised government in Nicosia says the guarantee system and the Turkish troop presence are anachronisms. It holds that the 1974 intervention was an unlawful use of force, and it refers to the northern part as occupied territory, citing European Court of Human Rights rulings, such as Loizidou v. Turkey and the 2001 Cyprus v. Turkey judgment, that found Türkiye responsible for acts there through effective control. It supports a bizonal, bicommunal federation per UN resolutions and rejects a two-state solution as a path to formal partition.

Greece

Athens remains a guarantor. It supports the Republic of Cyprus, favours dismantling the guarantee and intervention regime and withdrawing foreign troops, and rejects any settlement based on two states. Greece links Cyprus to its broader dispute with Türkiye in the Aegean and the Mediterranean; for the maritime dimension see Eastern Mediterranean Maritime Disputes: Continental Shelf, EEZ and Mavi Vatan Explained.

United Kingdom

The UK is both a guarantor and the holder of the Sovereign Base Areas. It formally supports a UN-led settlement based on a bizonal, bicommunal federation with political equality. In 2004, it offered to cede nearly half of the base-area territory as part of a settlement deal. London takes the position that it will not stand in the way of any arrangement the two communities reach, including changes to the guarantee system, and it has been willing to discuss the treaty’s future as part of an overall deal.

European Union

The EU treats the Republic of Cyprus as a member state and supports a comprehensive settlement within the UN framework, consistent with Security Council resolutions and EU principles. Council conclusions have repeatedly criticised unilateral steps in Varosha, the fenced-off quarter of Famagusta, and have rejected two-state formulas. Turkish officials argue that EU accession of a divided island, after the Greek Cypriot rejection of the Annan Plan, undermined its neutrality.

United Nations

The UN Security Council’s long-standing parameters are a bicommunal, bizonal federation with political equality (Resolution 1251 and later renewals), and it has termed the TRNC declaration legally invalid (Resolutions 541 and 550). UNFICYP has patrolled the buffer zone, or Green Line, of around 180 km (about 112 miles) since 1964. The Secretary-General’s Personal Envoy, María Ángela Holguín Cuéllar, has been working on restarting talks.

Turkish Cypriot leadership

Turkish Cypriot politics is diverse. For much of the 2020s, the leadership argued for two states with sovereign equality, while other parties and the newly elected president favour a renewed federal process, and both camps still cite the Treaty of Guarantee as a security reference point. Ankara, as the principal interlocutor, shapes outcomes through its security presence and economic ties, and it recognises the TRNC.

🇹🇷 Official Policy · Primary Sources

Türkiye's Position

The following summarises official Turkish policy as stated by Turkish government sources. It is Ankara’s position, not the neutral assessment of this journal.

• The treaty remains valid and Türkiye’s guarantor status stands. According to the Turkish Ministry of Foreign Affairs (MFA), the 1960 treaties remain the legal basis of the status of Cyprus, and Türkiye’s status as a guarantor, under the Treaty of Guarantee (Articles II and IV) and the Treaty of Alliance, cannot be removed unilaterally. Turkish officials say that effective and actual guarantees are a requirement of any settlement, given the events of 1963–74.
• The 1974 operation was a lawful exercise of Article IV. Ankara argues that the 15 July 1974 coup against the constitutional order, backed by Athens, violated Articles I and II’s ban on union, that consultation with the UK failed and that Türkiye therefore acted under Article IV to restore constitutional order and protect Turkish Cypriots. The MFA describes this as a ‘peace operation’ rather than an invasion.
• Turkish Cypriots are co-founders with equal status. The Presidency and the MFA stress that the 1960 Republic was a partnership of two equal peoples, and that this partnership was ended in 1963 when Turkish Cypriots were removed from state institutions. Ankara therefore regards the Greek Cypriot-led government in the south as not representing the whole island; it terms it the Greek Cypriot Administration of Southern Cyprus and does not recognise it.
• Sovereign equality and equal international status, and a two-state solution. President Erdoğan has stated at the UN General Assembly and in visits to the TRNC that, after decades of failed federation talks, a solution must be based on the realities on the island, meaning two states with sovereign equality and equal international status. Turkish officials point to the 2004 referendum, in which Turkish Cypriots voted yes and Greek Cypriots voted no, as evidence that Turkish Cypriots were left isolated while the Republic of Cyprus entered the EU. They regularly call for an end to the isolation of the TRNC and Turkish Cypriots.
• Crans-Montana is read as a Greek Cypriot failure to accept equality. Ankara says that the 2017 talks collapsed because the Greek Cypriot side was not ready to accept political equality or effective Turkish Cypriot participation and insisted on eliminating guarantees and troops. The Turkish side says that any new process must first accept the Turkish Cypriots’ equal status.

The Turkish position rests on the text of the 1960 treaties, on the 1963–74 events as Ankara interprets them and on the argument that UN resolutions treating the Greek Cypriot administration as the government were reached after Turkish Cypriots had been excluded. This position is rejected by the Republic of Cyprus, Greece, the EU and the UN Security Council on the points described above. For how Türkiye’s role as a NATO member interacts with these disputes, see Türkiye in NATO: Membership, Defense Industry and the Drone Factor.

Source Comparison

The same events are framed in different ways, and readers should compare primary documents with commentary.

Issue	Republic of Cyprus, Greece, EU framing	Turkish government framing	Neutral anchor
Terminology for 1974	‘Invasion’ and ‘occupation’	‘Peace Operation’ under Article IV	UNSC Res. 353 called for withdrawal of foreign forces other than those present under treaty
Status of the north	Occupied territory of the Republic of Cyprus	TRNC, a state of the Turkish Cypriot people	UNSC Res. 541 and 550: TRNC declaration legally invalid
Treaty of Guarantee	Obsolete; incompatible with the UN Charter and EU law	Valid and essential security guarantee	Text of Articles I–IV; no court ruling on validity
Origin of 1963 crisis	Turkish Cypriot withdrawal and rejection of reforms	Greek Cypriot seizure of the state and attacks on Turkish Cypriots	UNSC Res. 186 (1964) and UN Secretary-General reports
Annan Plan 2004	Turkish Cypriot yes was tactical; Greek Cypriots rejected a flawed plan	Turkish Cypriots said yes and were then left isolated	Referendum results: about 65% yes (Turkish Cypriot), about 76% no (Greek Cypriot)
Crans-Montana 2017	Turkish insistence on guarantees and troops blocked a deal	Greek Cypriot refusal of political equality and of guarantees	UN Secretary-General’s framework and closing statement

For discussion of how media framings can omit context, see Fact Check: Common Claims About Türkiye in International Media, and for how this journal handles sources, see Editorial Principles and Primary Source Standards.

Key Terms & Related Guides

• Enosis: the movement for union of Cyprus with Greece, prohibited by Articles I and II of the treaty.
• Taksim: the Turkish Cypriot-associated idea of partition, also prohibited by the treaty.
• Guarantor powers: Greece, Türkiye and the United Kingdom.
• Bizonal, bicommunal federation: the UN-endorsed framework, with two constituent states and political equality between the communities.
• TRNC: the Turkish Republic of Northern Cyprus, declared in 1983 and recognised only by Türkiye.
• UNFICYP / Green Line: the UN peacekeeping force and the buffer zone that divides the island.
• Sovereign Base Areas: the British-retained enclaves of Akrotiri and Dhekelia.

Related guides

• Eastern Mediterranean Maritime Disputes: Continental Shelf, EEZ and Mavi Vatan Explained: how the Cyprus issue overlaps with maritime claims.
• Montreux Convention and the Turkish Straits: A Plain-Language Guide: another treaty-based regime that Ankara regards as a pillar of its security.
• Türkiye in NATO: Membership, Defense Industry and the Drone Factor: Türkiye and Greece are both NATO allies.
• UN Security Council Reform: What 'The World Is Bigger Than Five' Means: Ankara’s views on UN decision-making.
• About Interstate Journal: Mission, Transparency and Editorial Team: our mission and editorial approach.

Interstate Journal presents global affairs with a dedicated perspective from Türkiye. Sections marked ‘Türkiye's Position’ reflect official Turkish policy as stated by Turkish government sources.

Cross-Publication Dossiers & Sister Desk Perspectives

For complementary primary-source analysis across our specialist editorial network, consult:

• Doctrine Review: Cyprus and the 1960 Treaty of Guarantee: What It Says and Why It Matters — The 1960 Treaty of Guarantee in Cyprus explained: what Article IV says, how 1963-74 unfolded, where the UN talks stand, and Türkiye's official position.
• Political Ledger: The Cyprus Issue: 1960 Treaty of Guarantee, Turkish Cypriot Equality and the Two-State Doctrine — Cyprus issue 1960 Treaty of Guarantee two-state solution explained: from EOKA and 1963 to 1974, the TRNC, failed federation talks, and each side's case.
• WorldPoliticsDaily: What Is the 1960 Treaty of Guarantee and Why Does It Matter for Cyprus? — The 1960 Treaty of Guarantee for Cyprus explained: its articles, guarantor rights, Ankara's 1974 legal case and the main counterarguments, with sources.