World Nuclear Non-Proliferation Index Methodology

There are six maps on our interactive application. Each of them was created using a separate methodology.

  • Nuclear Program Status — There are a total of 5 different categories indicating whether a country is an NPT nuclear-weapon state, a nuclear-weapon host state, a former nuclear-weapon host state, a state with a nuclear reactor(s), or a non-NPT nuclear-weapon state. Countries not falling into any of these categories are not colored.
  • Nuclear Weapons Count — There are a total of 4 different categories indicating whether a country is a nuclear-weapon host state, has 1+ nuclear weapons, has 1000+ nucler weapons, or has no weapons. Counties who have no nuclear reactors are not colored.e
  • Defense Spending Score — There are a total of 5 grades (A, B, C, D, F), indicating the level of a country's defense spending. The score is based on the combination of defense spending as a % of GDP and government spending. A percentile system was used to assign grades.
  • Nuclear Weapons Treaty Score — There are a total of 6 categories indicating whether a state signed 1-7 of the following treaties: Non-Proliferation Treaty, Comprehensive Nuclear-Test-Ban Treaty, Treaty on the Prohibition of Nuclear Weapons, Outer Space Treaty, Seabed Arms Control Treaty, Partial Nuclear Test Ban Treaty, and Nuclear Terrorism Convention.
  • Nuclear Energy Safety Treaty Score — There are a total of 4 categories indicating whether a state signed 0-3 of the following treaties: Convention on Nuclear Safety, Convention on the Physical Protection of Nuclear Material, and Joint Convention on the Safety of Spent Fuel Management.
  • Nuclear Energy Score — There are a total of 5 categories considering nuclear energy as a % of total energy. Countries that have no reactors or planned reactors are not colored.