In 1974 Kissinger was able to prepare his Cyprus coup first by deceiving everybody about his real intentions, including the Greek dictator Ioannides, Archbishop Makarios and Soviet FM Gromyko (when he met both of them in Nicosia weeks before the coup), the British government and even his own President Richard Nixon, probably exploiting his serious troubles with Watergate.
By essentially denying the principle of popular sovereignty, it is also denying the principle of national sovereignty, the (relatively) independent character of the Greek state. Greece occupies a strategic place in the Eastern Mediterranean, on the route connecting Russia with the Mediterranean and Western Europe with the Middle East. Its independence was never completely tolerated by the British and then the American empires. Greeks were also suspected of leaning towards Russians, or at least this was the argument justifying the innumerable Western interventions in this country.