Tensions between Greece and Bulgaria had been running high since the Balkan Wars and World War I, leaving the demilitarized border region near Petrich fraught with suspicion and military readiness. On October 18, 1925, a mundane pet incident transformed regional friction into an international crisis. A Greek soldier stationed along the frontier lost control of his dog, which darted across the border line into Bulgarian territory.
When the soldier ran across to retrieve his pet, Bulgarian sentries fired upon him, killing him instantly. A Greek captain rushed forward to inspect the situation under a white flag of truce, but he was shot and killed as well. Outraged by the deaths, the military dictator of Greece, General Theodoros Pangalos, issued a harsh ultimatum demanding compensation and a formal apology.
When Bulgaria refused, Greek troops crossed the border on October 22, invading Petrich and occupying several border villages. Bulgaria ordered its forces not to launch a full-scale counteroffensive, appealing instead to the newly formed League of Nations. Recognizing the threat of a wider Balkan conflict, the League acted rapidly, ordering an immediate cease-fire and sending military observers.
Greece was ordered to withdraw its forces and pay Bulgaria forty-five thousand pounds in damages, proving how a single runaway dog almost ignited a major European war.