When Cyprus became independent from Great Britain in 1960, the Treaty of Guarantee was signed between Cyprus, Greece, Turkey, and Great Britain. Article I bans Cyprus from unifying with another state. Article II requires Greece, Turkey, and the United Kingdom (the guarantor powers) to respect the territorial integrity of Cyprus. Article IV allows the guarantor powers to re-establish the status quo in Cyprus:

“In the event of a breach of the provisions of the present Treaty, Greece, Turkey and the United Kingdom undertake to consult together with respect to the representations or measures necessary to ensure observance of those provisions. In so far as common or concerted action may not prove possible, each of the three guaranteeing Powers reserves the right to take action with the sole aim of re-establishing the state of affairs created by the present Treaty.”

A Un Peacekeeping patrol in the Green Zone 2009, Dickelbers
UN Peacekeeping Forces at the Green Line in 2009 | Dickelbers, Wikimedia

When a pro-enosis (unification with Greece) coup took place in July 1974 in Cyprus, Turkey feared that Cyprus would be unified with Greece.  Despite the deposed Cypriot president, Archbishop Makarios, seeking intervention by the United Nations, Turkish forces invaded and occupied a small part of the island before a ceasefire was declared. Shortly thereafter, the Greek military junta collapsed and in August Turkey invaded again, this time occupying roughly the northern 40% of the island. The Green Line marks the southernmost point of occupation by the Turkish government and is today the effective border between Cyprus and the mostly internationally unrecognized Turkish Republic of Northern Cyprus. It even cuts straight through the Cypriot capital of Nicosia, the last divided capital in the world.

Although Turkey had nominally invaded to maintain peace under Article IV of the Treaty of Guarantee, what it created was a human rights disaster. Tens of thousands of ethnically Greek Cypriots were forced to flee from the north while Turkish Cypriots in the south had to go north. It was a forced population transfer and refugee crisis reminiscent of Turkey and Greece in 1923 under the Treaty of Lausanne. Communities were torn apart, people were uprooted, and Cypriot unity was shattered.

Map of Cyprus, CIA World Factbook
Map of Divided Cyprus | CIA World Factbook

The United Nations repeatedly issued resolutions to the effect that Turkey should remove its forces from the island. General Assembly Resolution 3212, issued on November 1, 1974, and backed up by a Security Council resolution the next month, urged all foreign troops to withdraw and cease foreign interference in the affairs of Cyprus. The next year, Resolution 3395 against urged all member states to comply with Resolution 3212 and withdraw their forces. Over the next twenty years, several more resolutions by both the General Assembly and the Security Council urged the withdrawal of foreign troops from the island, but to no avail. In Security Council Resolution 969 in 1994, the council noted that Cyprus was no closer to a peace settlement nor had the presence of foreign troops on the island been reduced.

Current Cyprus peace talks, which seemed to be heading in a positive direction last year, have stalled if not partially collapsed. The greatest challenge in reaching any sort of deal on reunification of the island is the Turkish military presence in the Turkish Republic of Northern Cyprus. By maintaining this presence, not only is Turkey harming reunification talks, but it is flouting international law. Although Turkey may have invaded with the intention of upholding Article IV of the Treaty of Guarantee, its continued presence on the island is in direct violation of Article II of that same treaty. In addition, Turkey has simply ignored UN resolutions. Although the UN resolutions may not carry the weight of binding law, the repeated calls for Turkey to withdraw its troops by both the General Assembly and the Security Council give these resolutions greater weight as part of customary international law. Since the treaty’s terms were not properly enforced by the other guarantors and even the presence of a UN peacekeeping force has not deterred the Turkish military presence on the island, in this case international law and the United Nations has failed Cyprus by not recognizing and acting on Turkey’s failure to comply with its treaty obligations and international law.