Devolution: The AMSCO textbook defines devolution as, "the transfer of some political power from the central government to subnational levels of government" (4.8). El Salvador doesn't have much devolution at all because it has a unitary government.
Ethnic Cleansing: There was an example of ethnic cleansing in El Salvador in 1932. "Zinn Education Project" states, "La Matanza (“The Massacre”) Begins in El Salvador. On January 22, 1932, in the Central American nation of El Salvador, 30,000 people — most of whom were indigenous — died at the hands of Salvadoran soldiers for protesting the government and the oppressive policies of president Maximiliano Hernández Martínez" (Jan. 22, 1932: La Matanza (“The Massacre”) Begins in El Salvador).
Terrorism: There haven't been any recent acts of terrorism against El Salvador. The last terrorist attack in El Salvador was on July 15, 1984: Terrorists attacked a train in El Salvador. They took measures to prevent things like this from happening in the future.
The UN states, "The Republic of El Salvador is submitting this report in pursuance of General Assembly resolution 73/211, by which the item entitled “Measures to eliminate international terrorism” was included in the provisional agenda of the seventy-fourth session of the General Assembly and under which all Member States have been asked to provide the Secretary-General with information concerning the status and implementation of existing multilateral, regional and bilateral agreements relating to international terrorism, including information on any incidents caused by international terrorism and any criminal prosecutions and sentencing...El Salvador has on many occasions expressed opposition to acts of terrorism and complete willingness to adopt any monitoring and international cooperation measures that may be necessary in order to ensure that such acts are prevented, investigated and prosecuted" (Measures to eliminate international terrorism Report of the Republic of El Salvador pursuant to General Assembly resolution 73/211).
Physical geography isn't an issue for El Salvador, as they are small and not an island so they have no issue of isolation/communication challenges.