The Central American War was a series of military conflicts between the pro-independence forces of Panama, Costa Rica, and Nicaragua (backed by the United States and Japan) and the pro-union forces of Honduras, El Salvador, and Guatemala. The war started in 1972 after the death of Director-General Manuel Mendoza. Panamanian forces immediately sought independence from the rest of the nation, which was always culturally different from Panama. The United States declared support for Panama as relations with the United Federation had slowly become hostile after the Fifth World War. By 1973, Nicaragua and Honduras had joined Panama in seeking independence, with American and now Japanese backing. Russia intervened on the side of the the Federation, seeking to maintain the presence of a major anti