Certain Activities Carried out by Nicaragua in the Border Area (Costa Rica v. Nicaragua); Construction of a Road in Costa Rica along the San Juan River (Nicaragua v. Costa Rica) International Decisions

On December 16, 2015, in joined proceedings in Certain Activities Carried Out by Nica- ragua in the Border Area (Costa Rica v. Nicaragua) and Construction of a Road in Costa Rica Along the San Juan River (Nicaragua v. Costa Rica), the International Court ofJustice resolved competing claims to a portion of the border area between the two states along the San Juan River, as well as allegations brought by each state accusing the other of violating the obligation to exercise due diligence to avoid causing significant transboundary harm.\u27 In the first case, the Court found that Costa Rica had sovereignty over the disputed territory, that Nicaragua had violated Costa Rica\u27s sovereignty by excavating three caios (channels) and establishing a mil- itary presence in the territory, and that Nicaragua had breached Costa Rica\u27s rights of navi- gation on the river. In the second, the Court found that Costa Rica had violated its obligations under general international law by failing to carry out an environmental impact assessment (EIA) on the construction of a road along a portion of the river