It seems that Turkey is trying to repair its badly damaged relations with Russia otherwise its deviation from NATO cannot be explained. The very country that recently was about to wage war against Russia by shooting down a Russian aircraft is contemplating spending billions of dollars on an air missile defense system (S400) that could have easily have been obtained from a NATO ally (presumably the USA). If the deal is closed then Greece’s air missile defense system S300, which is a generation older than S400, will not be able to compete with the state-of-the art S400 system. Besides, S400 are also antiballistic missile defenses which would protect Turkey from short, intermediate and long-range ballistic missiles. Such a deal would destabilize the military balance between Turkey and Greece causing a major arms control issue.