The Imia political crisis

In January of 1996, Greece and Turkey were on the verge of a declaration of war with their naval fleets in battle formation in the Aegean Sea.
The trigger for this was the shipwreck of the Turkish commercial boat "Figen Acat" in shallow waters near the Small Imia, an island that Turkey had included in the Turkish Land Registry.

The Mayor of Kalymnos, at the time, raised the Greek flag on the island. His act was followed by a group of Turkish journalists who landed on the island, took down the Greek flag and raised the Turkish flag. The events led to a Greek helicopter crash, tension escalated, and special forces from both countries landed on the two islands. Eventually, American intervention defused the situation.