Who are the relevant actors in the creation of Chile’s national foreign policy and what structures do they operate within?
Chile’s current Constitution was approved in a national plebiscite in 1980 during the military dictatorship. It has since been amended nine times, but retains the strong executive tradition common in Chile since the end of the Parliamentary Republic in 1925.
The government is divided between an executive branch, containing 20 ministries; a bicameral legislature, consisting of a 47 member Senate and a 120 member Chamber of Deputies; and a Judiciary branch. Foreign policy is controlled by the executive branch through the Ministry of Foreign Relations. This ministry is in charge of “planning, directing, coordinating, executing, and diffusing the foreign policy formulated by the President of the Republic.” 
It is responsible for coordinating all activities of all the other state ministries and public institutions as well as overseeing all issues related to national sovereignty including its marine and Antarctic territories. There is also a National Security Council, made up of the Presidents of the Senate, the Supreme Court and the Chiefs of each branch of the armed forces that advises the president of the Republic on defense issues. This division of powers gives the executive ample room to maneuver in international affairs. 
The current president of Chile is Michelle Bachelet (b.1951), a socialist, pediatrician and former health (2000 – 2002) and defense minister (2002 – 2004). Chile’s current Foreign Minister is Alejandro Foxley, a member of the Christian Democratic Party, an economist and a politician who previously served as a senator (1998 – 2006) and finance minister (1990 – 1994).
Vanden, Harry E. y Gary Prevost. Politics of Latin America: The Power Game. Oxford University Press: Oxford 2002: 446  Chilean Ministry of Foreign Relations. Website 17 Apr. 2008  Vanden and Prevost 2002: 459  President J.Prieto said to the Chilean Congress in 1832 “En el departamento de la Guerra y Marina, apénas tengo que añadir a lo que os espuso mi antecesor en 1.˚ de junio del año pasado. Llamo vuestra atención, como él lo hizo, a la seguridad de ámbas fronteras, a la necesidad de un método uniforme en la suministracion de vestuarios u en la remonta de la caballería, a la organización de la maestranza general de artilleria, a la lei de reemplazos, a la administración de justicia militar en última instancia, i al estado de las fuerzas navales.” Documentos Parlamentarios. Discursos de Apertura en las sesiones de Congreso, i Memorias Ministeriales correspondientes a la Administración Prieto (1831-1841). Tomo I. Imprenta del Ferrocarril. Santiago 1858: 4