Earlier this month, the Croatian Embassy in Slovenia sent leading Slovenian officials -- including officials in the offices of the prime minister and the president -- boxes of chocolates with labels reading "Greetings from Croatia."
But the Christmas gift wasn't appreciated.
The recipients' attention was drawn to a map on the box that showed an area disputed by the two countries as part of Croatia. Both Zagreb and Ljubljana claim the Gulf of Piran, or Piran Bay, in the northern reaches of the Adriatic Sea. Although Slovenia claims the entire bay, the Croatian chocolate box showed the border running right through its middle.
The two countries agreed to international arbitration of the dispute in 2009 as part of Croatia's bid to enter the European Union. But in July 2015, Croatia withdrew from the arbitration process, alleging improper contacts between an arbitration judge and Slovenian officials.
According to a Croatian news portal, the Slovenian Foreign Ministry sent all the chocolate boxes back to the Croatian Embassy in bags inscribed with the message "I feel Slovenia."
The gift spat is the Balkans' second unfortunate, chocolate-related incident this month.
The regional "chocolate war" started when Croatian President Kolinda Grabar-Kitarovic apologized after handing out Serbian-made chocolate to kindergarteners to mark Defenders of Dubrovnik Day on December 6. During the 1990s Balkans war, that coastal city was besieged for seven months and severely shelled by Serbian and Montenegrin forces.