The historic treaty between Nicaragua and Honduras

Recognizing the recent victory of President Daniel Ortega in Nicaragua is not the best look for governments in Latin America after he ordered the arrest of seven opposing candidates and used his political police to intimidate journalists ahead of the November 2021 presidential election. The Central American country is becoming increasingly isolated, with newly-elected left-wing leaders in Chile and Peru beginning to denounce Mr. Ortega’s authoritarianism. But there is one curious exception.

During the January 10 inauguration ceremony for Mr. Ortega’s fourth presidential term, sitting not too far from him, was Juan Orlando Hernández, who was in his last days as president of neighboring Honduras. 

Despite their entirely opposing views from an ideological standpoint, the pair have maintained an unexpectedly solid relationship — thanks almost completely to the Gulf of Fonseca.

The Gulf of Fonseca is a large inlet on Central America’s Pacific coast, serving as the convergence point between Nicaragua, Honduras, and El Salvador. For hundreds of years, it has...