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 backbone of Cyprus's independence, and it remains the most disputed document in the Cyprus problem. It created three guarantor powers (Greece, Türkiye and the United Kingdom) and, in Article IV, set out the conditions under which they may act. Every UN-led negotiation since 1974, including the failed talks at Crans-Montana in 2017, has turned partly on whether this system should be kept, reformed or abolished.

Background

The Zurich-London agreements (1959)

Cyprus was a British colony until 1960. After an armed Greek Cypriot campaign for union with Greece (enosis) and Turkish Cypriot calls for partition (taksim), Greece and Türkiye agreed a framework in Zurich on 1959-02-11. It was endorsed in London on 1959-02-19 by Greece, Türkiye, the United Kingdom and representatives of the Greek Cypriot and Turkish Cypriot communities, Archbishop Makarios III and Dr. Fazıl Küçük.

The settlement produced a package of instruments:

• The Constitution of the Republic of Cyprus: a Greek Cypriot President and a Turkish Cypriot Vice-President, each with defined veto powers over foreign affairs, defence and security. Parliament and the civil service were split 70:30, and the army 60:40.
• The Treaty of Establishment: the UK retained the Sovereign Base Areas of Akrotiri and Dhekelia.
• The Treaty of Guarantee: Cyprus, Greece, Türkiye and the UK.
• The Treaty of Alliance: Cyprus, Greece and Türkiye, stationing small national contingents on the island (950 Greek and 650 Turkish soldiers).

The Republic of Cyprus became independent on 1960-08-16.

What the Treaty of Guarantee says

• Article I: Cyprus undertakes to maintain its independence, territorial integrity, security and constitutional order, and renounces both union with any other state and partition.
• Article II: Greece, Türkiye and the UK recognise and guarantee that status and the state of affairs created by the basic articles of the Constitution. They also prohibit activity promoting union with another state or partition.
• Article IV: in the event of a breach, the three powers undertake to consult on measures to ensure observance. Where common or concerted action is not possible, each reserves "the right to take action with the sole aim of re-establishing the state of affairs created by the present Treaty."

The treaty text does not use the word "intervention," and it does not define the scope of permitted action. This ambiguity underlies most of the later legal argument.

Timeline

Date	Event
1959-02	Zurich and London agreements
1960-08-16	Republic of Cyprus founded; Treaties of Guarantee, Alliance and Establishment in force
1963-11/12	President Makarios proposes constitutional amendments; intercommunal violence begins and Turkish Cypriots leave state institutions
1964-03-04	UN Security Council Resolution 186 establishes UNFICYP, the UN peacekeeping force
1974-07-15	Coup against Makarios by the Greek junta-backed National Guard
1974-07-20	Türkiye intervenes, citing Article IV; a second phase follows in August; the island is divided along a ceasefire line
1983-11-15	Turkish Cypriot side proclaims the Turkish Republic of Northern Cyprus (TRNC); UNSC Resolution 541 calls the declaration legally invalid
2004-04-24	Annan Plan referendums: roughly two-thirds of Turkish Cypriots vote yes, about three-quarters of Greek Cypriots vote no
2004-05-01	Cyprus joins the EU; EU law is suspended in the north
2017-06/07	Crans-Montana conference under UN Secretary-General António Guterres ends without agreement

Key Players & Positions

Greek Cypriot side (Republic of Cyprus)

The Republic of Cyprus government argues that the 1974 Turkish military operation was an invasion and that the north remains under occupation. It holds that Article IV never authorised unilateral military action or the permanent presence of troops, and that guarantee rights are incompatible with the sovereignty of an EU member state and the UN Charter. Nicosia seeks the abolition of the Treaty of Guarantee and Treaty of Alliance and the withdrawal of Turkish troops as part of any settlement. It supports the UN framework of a bicommunal, bizonal federation with political equality.

Greece

Athens calls for a security regime that does not rely on unilateral guarantee rights or foreign troops, and it consistently rejects Ankara's two-state proposals. It remains a formal guarantor and party to the 1960 treaties.

United Kingdom

London remains a guarantor and retains the Sovereign Base Areas. It supports a UN-led settlement and has said it would not obstruct what the two communities agree. In the context of a deal, it has previously signalled willingness to cede part of the base territory. Its official line is that the guarantor powers can adapt the security arrangements if the parties agree.

United Nations and the European Union

Since Security Council Resolution 750 (1992), the UN has defined the goal as a bicommunal, bizonal federation with political equality. It also holds that the TRNC declaration is legally invalid (Resolution 541 of 1983, Resolution 550 of 1984). The EU treats the whole island as EU territory, with the acquis suspended in areas where the Republic's government does not exercise effective control.

Turkish Cypriots

Turkish Cypriot leaders have historically sought political equality and security guarantees. After the 2004 vote, which saw a majority back the Annan Plan and the Greek Cypriot electorate reject it, they argue they were left in international isolation.

Türkiye's Strategic Position

The points below reflect official Turkish policy as stated by the Turkish Ministry of Foreign Affairs (MFA) and the Presidency of the Republic of Türkiye.

• Guarantor rights are treaty-based and active. According to the Turkish Foreign Ministry, Türkiye's 1974 action (which Ankara calls the Cyprus Peace Operation) rested on Article IV of the Treaty of Guarantee after the coup of 1974-07-15 and the failure of consultation with the UK. Ankara argues the operation was a lawful response to a breach of the treaty, aimed at restoring constitutional order and protecting Turkish Cypriots.
• The 1960 partnership state ended in 1963. Ankara argues that the Turkish Cypriots, as one of two founding partners, were forced out of state institutions in 1963-64, and that the "Republic of Cyprus" has since been run solely by the Greek Cypriot administration. The MFA refers to it as the Greek Cypriot Administration of Southern Cyprus.
• Sovereign equality and the two-state vision. Since 2020-21, President Erdoğan has stated that decades of federation talks have not worked and that a durable solution must rest on the realities on the island: two peoples, two states, with sovereign equality and equal international status. Ankara has also called on the international community to end the isolation of the TRNC and Turkish Cypriots. Türkiye is the only state that recognises the TRNC.
• Effective guarantees remain a security red line. Ankara argues that the 1963-74 experience shows Turkish Cypriots cannot rely on paper assurances, and that the Treaty of Guarantee and Treaty of Alliance should not be withdrawn without a fully workable replacement. It holds that this was the main obstacle at Crans-Montana, and that Greek Cypriot unwillingness to accept political equality and effective guarantees prevented a deal in 2017.
• Hydrocarbon resources belong to both communities. Ankara says that the island's resources belong jointly to Greek and Turkish Cypriots, and that the Republic's unilateral licensing excludes the Turkish Cypriots. It backs the TRNC's licences to the Turkish Petroleum Corporation (TPAO) and the 2011 continental shelf delimitation agreement between Türkiye and the TRNC. It has proposed a joint mechanism for hydrocarbon decisions. For the wider maritime framework, see Eastern Mediterranean Maritime Jurisdiction: Continental Shelf, EEZ and the Blue Homeland.

Legal basis: Ankara relies on Articles II and IV of the Treaty of Guarantee, the 1959-60 basic structure of the Republic, and the 1974 breach of constitutional order. It also cites the principle of equal rights of the island's two peoples. It argues that the Greek Cypriot side's accession to the EU in 2004 without the Turkish Cypriots was inconsistent with the 1960 treaties.

Energy Resources and the Dispute over Shares

Cyprus's offshore gas has added a contested layer to the guarantee debate. The Republic of Cyprus has signed EEZ delimitation agreements with Egypt, Lebanon and Israel and licensed blocks to international companies, with discoveries including Aphrodite, Glaucus and Calypso. Its government says revenues will benefit all Cypriots, and has proposed a fund for Turkish Cypriots' share until a settlement. Turkish Cypriot leaders and Ankara say the Turkish Cypriots, as co-owners of the island, should take part in decisions on licences and revenues now. The EU has adopted a sanctions framework in response to Turkish drilling off Cyprus in 2019-20, which Ankara rejects as one-sided. For the wider gas picture, see Türkiye as an Energy Hub: Pipelines, Corridors and Transit Routes Explained.

Source Comparison

Issue	Greek Cypriot / Greek / EU framing	Turkish and Turkish Cypriot framing	Neutral anchor
1974	Invasion and occupation	Peace Operation under Article IV after the coup	UNSC Resolution 353 (1974) called for respect for Cyprus's sovereignty and for withdrawal of foreign forces
Treaty of Guarantee	Outdated, incompatible with sovereignty and EU membership	Valid treaty and the basis of Turkish Cypriot security	The treaty is in force and its Article IV is not defined further by its text
Status of the north	Illegal secession; TRNC invalid	Expression of Turkish Cypriot self-determination	UNSC Resolutions 541 and 550 call the declaration invalid
Solution	Bicommunal, bizonal federation	Two states, sovereign equality	UN framework remains a federation
Crans-Montana 2017	Turkish insistence on guarantees and troops ended the talks	Greek Cypriot refusal of political equality and effective guarantees	The UN Secretary-General reported that talks closed without agreement
Gas	Resources belong to the Republic; Turkish Cypriots share after settlement	Co-ownership, so joint decision-making now	No agreed mechanism exists

When reading media coverage, check whether the outlet quotes the treaty text itself. Many accounts paraphrase Article IV in a way that favours one reading. For a general guide to claims in international coverage, see Fact Check: Common Claims About Türkiye in International Media. Our sourcing standards are set out in Editorial Principles and Primary Source Standards.

Key Terms & Related Guides

• Guarantor powers: Greece, Türkiye and the UK under the 1960 Treaty of Guarantee.
• Enosis / Taksim: union with Greece / partition, both excluded by Article I.
• Bicommunal, bizonal federation (BBF): the UN-endorsed solution model, with two constituent states and political equality.
• UNFICYP: the UN Peacekeeping Force in Cyprus, created in 1964.
• Green Line / Buffer Zone: the UN-patrolled ceasefire line dividing the island.
• TRNC: Turkish Republic of Northern Cyprus, recognised only by Türkiye.
• Crans-Montana: the 2017 UN-convened conference that did not produce a settlement.

Related reading: Eastern Mediterranean Maritime Jurisdiction, UN Security Council Reform: What 'The World Is Bigger Than Five' Means, Doctrinereview FAQ: Sources, Methodology and Perspective and About Doctrinereview: Mission, Transparency and Editorial Team.

Doctrinereview presents global and regional affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Strategic 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:

• Interstate Journal: Cyprus and the 1960 Treaty of Guarantee: What It Says and Why It Matters — 1960 Treaty of Guarantee Cyprus explained: what Article IV allows, whether it is still valid and why the island is divided, from 1960 to the two-state debate.
• 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.
• The Global Anatomy: The Cyprus Issue Explained: 1960 Treaty of Guarantee and the Sovereign Equal Two-State Solution — Cyprus issue explained: from the 1960 Treaty of Guarantee to 1963, 1974 and the TRNC, plus every party's position and Türkiye's two-state solution case.