Ukraine natural resources in Ukraine include iron ore, coal, manganese, natural gas, oil, salt, sulphur, graphite, titanium, magnesium, kaolin, nickel, mercury, timber and an abundance of arable land. Despite this, the country faces a number of major environmental issues such as inadequate supplies of potable water; air- and water-pollution and deforestation, as well as radiation contamination in the north-east from the 1986 accident at the Chernobyl Nuclear Power Plant. Recycling toxic household waste is still in its infancy in Ukraine. From northwest to southeast the soils of Ukraine may be divided into three major aggregations: As much as two-thirds of the
Nuclear weapons and Ukraine of Independent States. In 1994 Ukraine agreed to destroy the weapons, and to join the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). As a republic in the Soviet Union, Ukraine was the base for the following nuclear forces: International relations theorist John Mearsheimer predicted a Ukraine without any nuclear deterrent was likely to be subjected to aggression by Russia, but this was very much a minority view at the time. A 2016 study argues that the denuclearization of Ukraine was not a "stupid mistake" and that it is unclear that Ukraine would be better off as a nuclear state.