In addition to Sofia's revisionism, Greece had to face further problems. In 1924-29, Yugoslavia pursued a hegemonist policy in the Balkans. It therefore claimed sovereign rights over the Serb free zone in the port of Thessaloniki and the Thessaloniki-Gevgelija railway, while it tried to infiltrate the Slavic-speakers who had remained in Greece after the exchange of populations.
To be sure, Greece's main problem was the Bulgarian claims, calling for a change of the borders. However, the Yugoslav demands, had they been accepted, could also have mortgaged Greek sovereignty in Macedonia.
Diplomatically isolated after the defeat of 1922, Greece was too weak to extricate herself from the welter of Bulgarian and Yugoslav pressures. Thus, Athens appeared to face a diplomatic impasse trying to safeguard its rights on Macedonia, rights which had been gained through international treaties.