The propaganda of the "Socialist Republic of Macedonia" was incompatible with regional stability. Furthermore, since the 1960s a new factor has been added to the many already affecting the Macedonian Question: the Slav-Macedonian diaspora in America, Canada and Australia launched intensive campaigns, claiming the existence of a historically traceable "Macedonian" ethnic group, as well as of "enslaved Macedonian minorities" in Bulgaria and Greece.
If the Slav-Macedonians, through their propaganda, merely insisted that they were a distinct ethnic group, there would be no problem for Greece. But the Slav-Macedonians' persistence in claiming the Hellenic heritage and linking the existence of this new ethnic group to its expansion into Greek-Macedonia (and this is precisely why they used the terms "Macedonia" and "Macedonian nation") could not but arouse the opposition of Greece.
However, Skopje's propaganda managed to gain ground internationally, as it was also associated with Cold War realities.