The Treaty of Osimo was signed to finally address and resolve the territorial disputes that emerged in the aftermath of World War II, particularly concerning Istria and the Free Territory of Trieste. After the war, the region experienced significant political tension, with both Yugoslavia and Italy laying claim to certain territories. Efforts to peacefully negotiate these disputes led to the treaty in 1975, following decades of ambiguity and conflict. The signing took place in Osimo, Italy, where representatives from both nations met to agree on a cooperative resolution and clear delineation of borders.

The treaty established that significant territories, including parts of Istria and the city of Trieste, would belong to Italy, while some border adjustments and areas would remain under Yugoslavia. This agreement was crucial, as it provided a formal legal framework to settle centuries-old rivalries and train the populations of both nations on shared governance. In addition, the treaty facilitated an increase in economic collaboration and cultural exchanges, laying the groundwork for improved relationships in the years following its signing.

In an important diplomatic context, the Treaty of Osimo was a significant indicator of the changing political mood in Europe during the 1970s, a period characterized by détente and constructive engagement. The agreement aimed not only to ease diplomatic tensions but also to strengthen the cooperative spirit of socialist Yugoslavia with the Western European nation of Italy. The long-term implications of the treaty fostered regional stability and positively contributed to post-war reconciliation efforts in Europe.