Why did the Belize-Guatemala territorial dispute continue after Belize became independent?

The territorial dispute between Belize and Guatemala originated from Guatemala’s claim that it inherited Spanish interests in the region, which Britain had occupied since the 17th century. Although an 1859 treaty defined boundaries between the two, the agreement became a source of long-term contention.12

The dispute became intractable after 1940, when Guatemala declared the 1859 treaty null and void, arguing that Britain had failed to fulfill a provision requiring the establishment of "the easiest communication" between the two territories. This unresolved claim persisted through Belize's transition to independence in 1981.1234

Despite Guatemala formally recognizing Belize as an independent state by the early 1990s, the territorial disagreement continued to resurface. Efforts to resolve the issue have included an Organization of American States (OAS)-assisted facilitation process in 2002, which Guatemala rejected. In 2008, both nations agreed to submit the case to the International Court of Justice, contingent upon approval via referenda in both countries.34