They engaged in a systematic campaign of terror among the rural Nicaraguan population to disrupt the social reform projects of the Sandinistas. Several historians have criticized the contra campaign and the Reagan administration's support for the Contras, citing the brutality and numerous human rights violations of the contras. LaRamee and Polakoff, for example, describe the destruction of health centers, schools, and cooperatives at the hands of the rebels, and others have contended that murder, rape, and torture occurred on a large scale in contra-dominated areas. The United States also carried out a campaign of economic sabotage, and disrupted shipping by planting underwater mines in Nicaragua's port of Corinto, an action condemned by the International Court of Justice as illegal.  The court also found that the U.S. encouraged acts contrary to humanitarian law by producing the manual ''Psychological Operations in Guerrilla Warfare'' and disseminating it to the contras. The manual, amongst other things, advised on how to rationalize killings of civilians. The U.S. also sought to place economic pressure on the Sandinistas, and the Reagan administration imposed a full trade embargo.