Türkiye and Greece have been in a conflictual relationship since the emergence of the Cyprus question, which is at the heart of the strained Turkish-Greek bilateral relations, in the early 1960s. Shortly after the independence of Cyprus Island from British rule, the Greek majority first began to sideline the Turkish minority, then tried to intimidate and oppress them. While Greece supported the repressive policies of the Greek Cypriots, Türkiye, as a guarantor state, tried to prevent the atrocities against the Turkish minority. Then, other issues, mainly emanating from the Aegean Sea, contributed to the tension.
The tension between these two countries did not turn into a regional war, mainly due to their membership in NATO and the balancing policy of the NATO security provider (the United States). The U.S. intervened and eased the tension whenever it rose in Turkish-Greek relations.
However, recently the U.S. has dramatically changed its policy in favor of the Greek side. First of all, the U.S. has recently established nine different military bases on the Greek territories. Second, the U.S. has sent a cache of weapons to Greece, some of which were allocated on the Aegean islands. Thus, the U.S. government has indirectly supported Greece’s breach of international law. According to international treaties, these islands have a demilitarized status.
Third, the U.S. has lifted the long-time arms embargo against the Greek Cypriots. Fourth, the U.S. has been following an anti-Türkiye policy not only in the Eastern Mediterranean but also in the Middle East, i.e., the Syrian crisis. It has been supporting the YPG/PYD, the Syrian branch of the PKK, by all means.
The U.S. and other Western countries remain indifferent to the Greek provocations not only against Türkiye but also against the NATO military operations. For instance, Greece has challenged the NATO alliance by harassing Turkish aircrafts. Greek surface-to-air missiles (S-300) locked onto the Turkish F-16 fighter jets carrying out a reconnaissance mission in international airspace. Still, no Western country criticized Greece for this provocation.
When asked about a protest by Türkiye against the U.S. for providing Greece with military vehicles, the U.S. State Department spokesperson Ned Price admitted that the U.S. is implementing a double standard on provisions of its military sales to Greece and Türkiye. When asked about the use of different standards toward its allies, Price pointed out that "the standard we use is what is in America’s national interests." In other words, Price has admitted that the recently changed American policies toward the region have tilted in favor of Greece and the U.S. has become part of the regional tension.
Some Greek political circles are unhappy with the U.S. military investments in Greece since they know how difficult it is to get rid of these foreign troops from their lands. Some even claim that the U.S. has been transferring Greece into a front country, open to different threats, as an alternative to Türkiye, which served as a front country throughout the Cold War against the Soviet Union. That is, some consider the American military buildup in Greece as a measure in order to decrease Türkiye's relevance in NATO. However, they forget there is a huge difference between Greece and Türkiye and their contribution to the alliance. Greece can never fill the military gap created by Türkiye. Therefore, such attempts will be fruitless for the alliance.
Although the Ukrainian-Russian War is considered as the biggest for NATO, the Turkish-Greek tension also threatens the future of the alliance due to the biased policies of the U.S in favor of Greece. A hot war between the two countries may cause cracks and crises within the alliance. It seems that the U.S. does not mind losing Türkiye, which will have a severe drawback to the future of the alliance and its cost will be quite high.
Even though NATO has been trying to mediate between the two countries and calling them not to escalate the tension, it does not have an independent, effective mechanism to prevent an inter-ally conflict. If NATO does not solve conflicts between its allies, the alliance may be paralyzed. Soon, the Ukrainian-Russian War may also force NATO allies to follow different, if not conflictual, policies. Therefore, NATO has to develop a military or a political mechanism to resolve intra-alliance conflicts. In other words, the escalation of the Turkish-Greek conflict may force NATO to make some reforms to prevent crises within the alliance.