The 1964 developments in Cyprus constituted an important turning point in Turkish-Soviet relations. The neutrality policy of Makarios, the leader of the Greek Cypriot side, pleased the Soviet Union and was especially in line with their Eastern Mediterranean strategy. During this period, the Soviets consistently supported Makarios and opposed Turkey's intervention in Cyprus. The Soviets' biggest concern was the possibility of Cyprus becoming a NATO base in case Turkey took control of the island, even if only partially. At the time, the Soviet Union did not consider the issues regarding Turkey's right to intervene in Cyprus. However, the Soviets were "against foreign intervention" and argued that the Greek and Turkish communities should resolve their own issues among themselves. With this stance, it is understood that the Soviets actually supported and even wanted the domination of the Greek Cypriot community in Cyprus. However, this stance was in complete contradiction with Turkey's policy of protecting and supporting the Turkish Cypriot community. Just as the Johnson letter of June 5, 1964 was a turning point in Turkish-American relations and led to a change in the structure of these relations, this letter put Turkish-Soviet relations into a new and different period of development.
The real thaw in Turkish-Soviet relations began after the Cyprus crisis of 1964 and Khrushchev's fall from power in October. Khrushchev had been friendly towards Makarios since he perceived himself as the only one who could ensure Cyprus' non-compliance and independence. However, the new Soviet leadership prioritized relations with Turkey. Foreign Minister Feridun Erkin visited Moscow in late October 1964, and a joint communiqué issued at the end of the visit stated that both countries respected the independence of Cyprus and recognized "the legitimate rights of the two national communities". The message of the Johnson letter was not only contrary to the spirit of alliance, but also caused Turkey's foreign policy to question both the attitude of its northern neighbor and its commitment to the western bloc from 1945 until the Johnson letter. After the tense period of the 1950s, Turkish-Soviet relations regained momentum with Feridun Cemal Erkin's visit to Moscow in 1964. However, after this visit, Turkish-Soviet relations became complicated. The November 6 declaration issued at the end of the visit emphasized two main issues: First, that Turkish-Soviet relations should be based on the fundamental principle of peaceful coexistence; and second, that the Soviets, despite their opposition to foreign intervention in Cyprus, recognized the existence of two separate national communities on the island. At the end of the visit, Turkish Foreign Minister Feridun Cemal Erkin informed the Turkish Grand National Assembly that there were differences of opinion on Cyprus prior to the visit, but during the meeting, these differences were overcome through detailed information and negotiations and there was a remarkable similarity of views.
By 1964, the Cyprus issue continued to be a determining factor in Turkish-Soviet relations. The Soviet Union continued to oppose Turkey's intervention in the island, arguing that the Turkish and Greek communities in Cyprus should solve their own problems. During this period, the Soviet Union's Cyprus policy focused on the independence and territorial integrity of the island. The Soviets believed that any foreign intervention in Cyprus would destabilize the region.During the crisis in 1964, the Soviet Union's attitude towards Cyprus reflected its efforts to maintain a balance between the Turkish and Greek Cypriot communities on the island. During this period, the Soviets continued to support the Greek Cypriot leader Makarios and took a firm stance against Turkish military intervention. The Soviet Union emphasized that Cyprus remaining an independent and non-aligned country was critical for regional balances.1965 marked the beginning of a new chapter in Turkish-Soviet relations. The Soviet Union made various diplomatic attempts to improve its relations with Turkey. Within this framework, Soviet officials who visited Turkey in 1965 expressed their desire to increase economic and cultural cooperation between the two countries. These visits paved the way for a warmer period in Turkish-Soviet relations. However, the Cyprus issue was still a source of tension in the relations between the two countries. Turkey's determination to protect the Turkish Cypriot community and the Soviet Union's insistence on the island's independence caused diplomatic crises from time to time. The 1967 Cyprus crisis exacerbated this tension in Turkish-Soviet relations. Turkey's threat of military intervention in Cyprus provoked the Soviet Union's reaction. The Soviet Union urged Turkey to refrain from military actions in Cyprus and emphasized that the problem in Cyprus should be solved peacefully. During this period, the Soviet Union's stance on Cyprus further increased the tension in relations with Turkey. Greece's concern about the rise of leftist parties and currents within the country prepared the ground for the necessity of a coup d'état for the military cadre in Greece. On April 21, 1967, a military coup took place in Greece under the leadership of Colonel George Papadopoulos, who was an ultra-nationalist, anti-communist and advocated the revival of Hellenism. With the coup, the Greek parliament was dissolved. The military regime that seized power in Greece needed a foreign policy success in order to gain the support of the national public opinion and consolidate its power. For this reason, the military regime decided to enter into negotiations with Turkey in order to solve the Cyprus issue through diplomatic means, and in this direction, the Prime Ministers of Turkey and Greece came together in Keşan and Alexandroupoli on September 9-10, 1967 to discuss the problem. In 1967, under the presidency of Süleyman Demirel, negotiations between the two states began. Keşan and Alexandroupolis meetings were held with the Greek Prime Minister. On September 9th in Keşan and on September 10th in Alexandroupoli. During the negotiations, Greece offered to give Turkey bases in Cyprus in return for the island's unification with Greece. However, when this offer was rejected by Turkey, no consensus was reached between the parties and no outcome was reached. On November 15, 1967, the National Guard led by Grivas attacked the Turkish enclave of Kophinou. The impending Turkish intervention was blocked by the US government. Experienced diplomat Cyrus Vance was sent to Ankara and Athens to mediate tensions through 'shuttle diplomacy' In its secret session held on November 16-17, 1967, the Turkish Grand National Assembly discussed the latest developments in Cyprus and at the end of the session, the necessary authorization was given to the government for a military intervention in Cyprus.
During the 1967 Cyprus crisis, the Soviet Union's attitude towards Turkey was much softer than during the 1964 crisis. The fact that the fascist Colonels' Junta was in power in Greece also played a role in this attitude. If Enosis was realized, Cyprus would also be under the colonels' rule and would turn into a NATO base in real terms. For this reason, the Soviet Union opposed enosis from the very first moment, stating that the problem was "closely related to the reactionary policy of reactionary Greek circles who wanted to turn the island into a NATO war base" and that a solution should be found on the basis of the sovereignty, independence and territorial integrity of the Republic of Cyprus. Although the Soviet Union supported Makarios and the independent Republic of Cyprus with its territorial integrity preserved, it used a very moderate tone, avoiding confrontation with Turkey.Another indication of the common position of Moscow and Ankara on Cyprus was the official visit of President Cevdet Sunay to the USSR between November 12-21, 1969. During this visit, which attracted attention as the first visit from Turkey to the USSR at the presidential level, the independence of Cyprus and the existence of two national communities were reaffirmed in the joint declaration issued between the bilateral powers. Soviet-Cypriot developments also took place during this period. Following the signing of an agreement on economic and military cooperation between the USSR and the Republic of Cyprus in September 1964, Makarios officially visited the Soviet Union in 1971. On this occasion, Moscow reaffirmed its full support for Cyprus against any foreign intervention. The declaration issued at the end of the visit referred to the Cypriot people rather than the two communities and called for the withdrawal of all foreign troops from Cyprus. In fact, in a way, the Soviets were hinting at a federation. During the Lisbon session of NATO in 1971, Greece and Turkey negotiated a series of agreements on the Cyprus issue. According to one of the conditions, the Greek government proposed the creation of a ministerial (or deputy ministerial) position within the Cypriot government responsible for the autonomy of the Turkish community. On July 15, 1974, a coup d'état orchestrated by the Athens-backed EOKA and led by Nikos Sampson aimed to overthrow President Makarios of Cyprus. Sampson, who had strong support from the Greek government, had two primary objectives: to oust Makarios from power and to achieve Enosis by removing the Turkish population from the island. As a result of the coup, Sampson successfully took control, and Makarios was forced to flee the island using a British helicopter. The Greeks had made a strategic mistake; they were fighting for power and for Enosis. Bloody clashes broke out on the island, both among the Greeks and between the Greeks and Turks. Ankara could no longer remain passive. The Turkish Parliament took a decision, Ecevit went to London to "intervene" together with the UK, but London rejected a joint intervention. And Turkey intervened on July 20, l974 with its naval and air forces and landed on the island. This intervention was Turkey's "right" arising from the Zurich and London Treaties. As a guarantor country, it could fulfill what it should have done in 1963 only in 1974. The USSR adopted an extremely cautious attitude towards Turkey's Cyprus operation. It refrained from condemning this operation. It emphasized the independence, integrity and non-alignment of the island and the equal rights of the two peoples. The Turkish military presence on the island created problems within NATO. In this sense, it was in the USSR's interest that the problem remained unresolved. Cyprus, a problem involving the non-aligned Makarios and one of the largest communist parties in the Middle East (AKEL), never played a decisive role in bilateral relations. In 1975, the Greek lobby succeeded in influencing US foreign policy. As a result, an embargo was imposed on arms shipments to Turkey. Turkey reacted by closing the American military bases on its territory. This greatly irritated Washington D.C. and further divided the western defense system, but at the same time created a sense of satisfaction in Moscow. The embargo was lifted at the end of 1978 and the military bases resumed operations. After the Johnson letter in 1964, Ankara would receive a second blow from the US with the arms embargo. The main reason for lifting the arms embargo in 1978 was that Iran was in turmoil in 1978 and an anti-American religious regime was clearly coming. In this situation, the US would not be able to use the "facilities" it had built in the Elbrus Mountains to eavesdrop on the Soviet Union. It had to provide this system through Turkey. In a twist of fate, the revolution of the "mullahs" led the US to lift the embargo. The 1975-1978 American arms embargo taught Turkey something new. The Turkish Armed Forces could not be kept so dependent on foreign arms. For the first time, Turkey was taking serious steps towards establishing a national defense industry and diversifying its arms purchases. The national defense industry, which had started with Marshall Aid in 1947 and had been forgotten with the entry into NATO, was back on the agenda. As a conclusion, the Republic of Turkey has done its best to protect the rights and interests of the Turkish community on the island of Cyprus. Since the 1960s until today, the two-state solution has been the most rational solution and the sovereignty of the Turkish and Greek Cypriot communities has been taken into account. Turkish Foreign Policy has always been based on regional and global peace. Indeed, as the founding leader Mustafa Kemal Atatürk said, "Peace at home, peace in the world".