During the spring of 1974, Cypriot intelligence found evidence that EOKA B was planning a coup and was being supplied, controlled, and funded by the military government in Athens. EOKA B was banned, but its operations continued underground. Early in July, Makarios wrote to the president of Greece demanding that the remaining 650 Greek officers assigned to the National Guard be withdrawn. He also accused the junta of plotting against his life and against the government of Cyprus. Makarios sent his letter (which was released to the public) to the Greek president on July 2, 1974; the reply came thirteen days later, not in the form of a letter but in an order from Athens to the Cypriot National Guard to overthrow its commander in chief and take control of the island.

Makarios narrowly escaped death in the attack by the Greek-led National Guard. He fled the presidential palace and went to Paphos. A British helicopter took him the Sovereign Base Area at Akrotiri, from where he went to London. Several days later, Makarios addressed a meeting of the UN Security Council, where he was accepted as the legal president of the Republic of Cyprus.

In the meantime, the notorious EOKA terrorist Nicos Sampson was declared provisional president of the new government. It was obvious to Ankara that Athens was behind the coup, and major elements of the Turkish armed forces went on alert. Turkey had made similar moves in 1964 and 1967, but had not invaded. At the same time, Turkish prime minister Bülent Ecevit flew to London to elicit British aid in a joint effort in Cyprus, as called for in the 1959 Treaty of Guarantee, but the British were either unwilling or unprepared and declined to take action as a guarantor power. The United States took no action to bolster the Makarios government, but Joseph J. Sisco, Under Secretary of State for Political Affairs, went to London and the eastern Mediterranean to stave off the impending Turkish invasion and the war between Greece and Turkey that might follow. The Turks demanded removal of Nicos Sampson and the Greek officers from the National Guard and a binding guarantee of Cypriot independence. Sampson, of course, was expendable to the Athens regime, but Sisco could get an agreement only to reassign the 650 Greek officers.

As Sisco negotiated in Athens, Turkish invasion ships were already at sea. A last-minute reversal might have been possible had the Greeks made concessions, but they did not. The intervention began early on July 20, 1974. Three days later the Greek junta collapsed in Athens, Sampson resigned in Nicosia, and the threat of war between NATO allies was over, but the Turkish army was on Cyprus.

Konstantinos Karamanlis, in self-imposed exile in France since 1963, was called back, to head the Greek government once more. Clerides was sworn in as acting president of the Republic of Cyprus, and the foreign ministers of the guarantor powers met in Geneva on July 25 to discuss the military situation on the island. Prime Minister Ecevit publicly welcomed the change of government in Greece and seemed genuinely interested in eliminating the tensions that had brought the two countries so close to war. Nevertheless, during the truce that was arranged, Turkish forces continued to take territory, to improve their positions, and to build up their supplies of war matériel.

A second conference in Geneva began on August 10, with Clerides and Denktas as the Cypriot representatives. Denktas proposed a bizonal federation, with Turkish Cypriots controlling 34 percent of island. When this proposal was rejected, the Turkish foreign minister proposed a Turkish Cypriot zone in the northern part of the island and five Turkish Cypriot enclaves elsewhere, all of which would amount once again to 34 percent of the island's area. Clerides asked for a recess of thirty-six to forty-eight hours to consult with the government in Nicosia and with Makarios in London. His request was refused, and early on August 14 the second phase of the Turkish intervention began. Two days later, after having seized 37 percent of the island above what the Turks called the "Atilla Line," the line that ran from Morphou Bay in the northwest to Famagusta (Gazimagusa) in the east, the Turks ordered a ceasefire.

The de facto partition of Cyprus resulting from the Turkish invasion, or intervention, as the Turks preferred to call their military action, caused much suffering in addition to the thousands of dead, many of whom were unaccounted for even years later. An estimated one-third of the population of each ethnic community had to flee their homes. The island's economy was devastated.

Efforts were undertaken immediately to remedy the effects of the catastrophe. Intensive government economic planning and intervention on both sides of the island soon improved living standards and allowed the construction of housing for refugees. Both communities benefited greatly from the expansion of the tourist industry, which brought millions of foreign visitors to the island during the 1980s. The economic success of the Republic of Cyprus was significant enough to seem almost miraculous. Within just a few years, the refugees had housing and were integrated in the bustling economy, and Greek Cypriots enjoyed a West European standard of living. Turkish Cypriots did not do as well, but, working against an international embargo imposed by the Republic of Cyprus and benefiting from extensive Turkish aid, they managed to ensure a decent standard of living for all members of their community--a standard of living, in fact, that was higher than that of Turkey. Both communities established government agencies to provide public assistance to those who needed it and built modern education systems extending to the university level.